[Extensions Cleanup] Move ExtensionApiTest to extensions namespace

Move the ExtensionApiTest class into the extensions namespace, and
updated affected sites.

This CL should have no functional change.

Bug: 117261
[email protected] (/chrome)
[email protected] (/third_party/liblouis)

Change-Id: Ibd8820f47ebe53140fd725fb00b1d75c9872808c
Reviewed-on: https://chromium-review.googlesource.com/1050580
Commit-Queue: Devlin <[email protected]>
Reviewed-by: Istiaque Ahmed <[email protected]>
Cr-Commit-Position: refs/heads/master@{#558534}
diff --git a/chrome/browser/chromeos/extensions/action_handlers/action_handlers_apitest.cc b/chrome/browser/chromeos/extensions/action_handlers/action_handlers_apitest.cc
index cb3caf3..3ef48370 100644
--- a/chrome/browser/chromeos/extensions/action_handlers/action_handlers_apitest.cc
+++ b/chrome/browser/chromeos/extensions/action_handlers/action_handlers_apitest.cc
@@ -11,7 +11,7 @@
 
 namespace app_runtime = extensions::api::app_runtime;
 
-using ActionHandlersBrowserTest = ExtensionApiTest;
+using ActionHandlersBrowserTest = extensions::ExtensionApiTest;
 
 IN_PROC_BROWSER_TEST_F(ActionHandlersBrowserTest, LaunchAppWithNewNote) {
   // Load the app. Make sure to wait until it is done loading.
diff --git a/chrome/browser/chromeos/extensions/echo_private_apitest.cc b/chrome/browser/chromeos/extensions/echo_private_apitest.cc
index 27bf183..173b076 100644
--- a/chrome/browser/chromeos/extensions/echo_private_apitest.cc
+++ b/chrome/browser/chromeos/extensions/echo_private_apitest.cc
@@ -22,7 +22,7 @@
 
 namespace chromeos {
 
-class ExtensionEchoPrivateApiTest : public ExtensionApiTest {
+class ExtensionEchoPrivateApiTest : public extensions::ExtensionApiTest {
  public:
   enum DialogTestAction {
     DIALOG_TEST_ACTION_NONE,
@@ -39,7 +39,7 @@
   ~ExtensionEchoPrivateApiTest() override {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
 
     // Force usage of stub cros settings provider instead of device settings
     // provider.
diff --git a/chrome/browser/chromeos/extensions/file_manager/file_browser_handler_api_test.cc b/chrome/browser/chromeos/extensions/file_manager/file_browser_handler_api_test.cc
index 9988de4..9aac25a1 100644
--- a/chrome/browser/chromeos/extensions/file_manager/file_browser_handler_api_test.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/file_browser_handler_api_test.cc
@@ -163,7 +163,7 @@
 };
 
 // Extension api test for the fileBrowserHandler extension API.
-class FileBrowserHandlerExtensionTest : public ExtensionApiTest {
+class FileBrowserHandlerExtensionTest : public extensions::ExtensionApiTest {
  protected:
   void SetUp() override {
     // Create mount point directory that will be used in the test.
@@ -173,7 +173,7 @@
     tmp_mount_point_ = scoped_tmp_dir_.GetPath().Append("tmp");
     base::CreateDirectory(tmp_mount_point_);
 
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   // Creates new, test mount point.
diff --git a/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc b/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
index 7a867c1..550b6eb 100644
--- a/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/file_manager_private_apitest.cc
@@ -164,7 +164,7 @@
 
 }  // namespace
 
-class FileManagerPrivateApiTest : public ExtensionApiTest {
+class FileManagerPrivateApiTest : public extensions::ExtensionApiTest {
  public:
   FileManagerPrivateApiTest() : disk_mount_manager_mock_(nullptr) {
     InitMountPoints();
@@ -177,7 +177,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
 
     testing_profile_.reset(new TestingProfile());
     event_router_.reset(new file_manager::EventRouter(testing_profile_.get()));
@@ -189,12 +189,12 @@
     event_router_.reset();
     testing_profile_.reset();
 
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   // ExtensionApiTest override
   void SetUpInProcessBrowserTestFixture() override {
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
     disk_mount_manager_mock_ = new chromeos::disks::MockDiskMountManager;
     chromeos::disks::DiskMountManager::InitializeForTesting(
         disk_mount_manager_mock_);
@@ -214,7 +214,7 @@
     chromeos::disks::DiskMountManager::Shutdown();
     disk_mount_manager_mock_ = nullptr;
 
-    ExtensionApiTest::TearDownInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::TearDownInProcessBrowserTestFixture();
   }
 
  private:
diff --git a/chrome/browser/chromeos/extensions/info_private_apitest.cc b/chrome/browser/chromeos/extensions/info_private_apitest.cc
index ce47d4d..9217aed 100644
--- a/chrome/browser/chromeos/extensions/info_private_apitest.cc
+++ b/chrome/browser/chromeos/extensions/info_private_apitest.cc
@@ -22,7 +22,7 @@
 
 }  // namespace
 
-class ChromeOSInfoPrivateTest : public ExtensionApiTest {
+class ChromeOSInfoPrivateTest : public extensions::ExtensionApiTest {
  public:
   ChromeOSInfoPrivateTest() {}
   ~ChromeOSInfoPrivateTest() override {}
@@ -133,7 +133,7 @@
   ~ChromeOSArcInfoPrivateTest() override = default;
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     // Make ARC enabled for ArcAvailable/ArcEnabled tests.
     arc::SetArcAvailableCommandLineForTesting(command_line);
   }
diff --git a/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc b/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
index 399729e..fe78dbb 100644
--- a/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
+++ b/chrome/browser/chromeos/extensions/input_method_apitest_chromeos.cc
@@ -76,7 +76,7 @@
   content::NotificationRegistrar registrar_;
 };
 
-class ExtensionInputMethodApiTest : public ExtensionApiTest {
+class ExtensionInputMethodApiTest : public extensions::ExtensionApiTest {
  public:
   ExtensionInputMethodApiTest() {
     scoped_feature_list_.InitAndEnableFeature(features::kOptInImeMenu);
@@ -85,7 +85,7 @@
   ~ExtensionInputMethodApiTest() override {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         "ilanclmaeigfpnmdlgelmhkpkegdioip");
diff --git a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
index 3f0b0cd99..f9667f0 100644
--- a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
+++ b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
@@ -6,12 +6,12 @@
 #include "chromeos/cryptohome/system_salt_getter.h"
 #include "net/dns/mock_host_resolver.h"
 
-class WallPaperApiTest : public ExtensionApiTest {
+class WallPaperApiTest : public extensions::ExtensionApiTest {
  public:
   ~WallPaperApiTest() override = default;
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("a.com", "127.0.0.1");
   }
 };
diff --git a/chrome/browser/chromeos/extensions/wallpaper_private_apitest.cc b/chrome/browser/chromeos/extensions/wallpaper_private_apitest.cc
index 8e73a51..1f5653e5 100644
--- a/chrome/browser/chromeos/extensions/wallpaper_private_apitest.cc
+++ b/chrome/browser/chromeos/extensions/wallpaper_private_apitest.cc
@@ -6,12 +6,12 @@
 #include "chromeos/cryptohome/system_salt_getter.h"
 #include "net/dns/mock_host_resolver.h"
 
-class WallPaperPrivateApiTest : public ExtensionApiTest {
+class WallPaperPrivateApiTest : public extensions::ExtensionApiTest {
  public:
   ~WallPaperPrivateApiTest() override = default;
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("a.com", "127.0.0.1");
   }
 };
diff --git a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
index 2d3645b3a..a6b9c378 100644
--- a/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
+++ b/chrome/browser/chromeos/file_manager/external_filesystem_apitest.cc
@@ -273,7 +273,7 @@
 };
 
 // Base class for FileSystemExtensionApi tests.
-class FileSystemExtensionApiTestBase : public ExtensionApiTest {
+class FileSystemExtensionApiTestBase : public extensions::ExtensionApiTest {
  public:
   enum Flags {
     FLAGS_NONE = 0,
@@ -286,7 +286,7 @@
 
   void SetUp() override {
     InitTestFileSystem();
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpOnMainThread() override {
@@ -299,12 +299,12 @@
         .WillByDefault(testing::Return(true));
     CastConfigClientMediaRouter::SetMediaRouterForTest(&media_router_);
 
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
   }
 
   void TearDownOnMainThread() override {
     CastConfigClientMediaRouter::SetMediaRouterForTest(nullptr);
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   // Runs a file system extension API test.
diff --git a/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.cc b/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.cc
index 783d642e..259d925 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.cc
@@ -551,7 +551,7 @@
 
 void FileManagerBrowserTestBase::SetUp() {
   net::NetworkChangeNotifier::SetTestNotificationsOnly(true);
-  ExtensionApiTest::SetUp();
+  extensions::ExtensionApiTest::SetUp();
 }
 
 void FileManagerBrowserTestBase::SetUpCommandLine(
@@ -573,11 +573,11 @@
   command_line->AppendSwitch(chromeos::switches::kDisableZipArchiverUnpacker);
   command_line->AppendSwitch(chromeos::switches::kDisableZipArchiverPacker);
 
-  ExtensionApiTest::SetUpCommandLine(command_line);
+  extensions::ExtensionApiTest::SetUpCommandLine(command_line);
 }
 
 void FileManagerBrowserTestBase::SetUpInProcessBrowserTestFixture() {
-  ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+  extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
 
   local_volume_ = std::make_unique<DownloadsTestVolume>();
 
@@ -592,7 +592,7 @@
 }
 
 void FileManagerBrowserTestBase::SetUpOnMainThread() {
-  ExtensionApiTest::SetUpOnMainThread();
+  extensions::ExtensionApiTest::SetUpOnMainThread();
   CHECK(profile());
 
   CHECK(local_volume_->Mount(profile()));
diff --git a/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.h b/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.h
index 836e9ca..9969922a 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.h
+++ b/chrome/browser/chromeos/file_manager/file_manager_browsertest_base.h
@@ -33,7 +33,7 @@
 class FakeTestVolume;
 class LocalTestVolume;
 
-class FileManagerBrowserTestBase : public ExtensionApiTest {
+class FileManagerBrowserTestBase : public extensions::ExtensionApiTest {
  protected:
   FileManagerBrowserTestBase();
   ~FileManagerBrowserTestBase() override;
diff --git a/chrome/browser/chromeos/login/auto_launched_kiosk_browsertest.cc b/chrome/browser/chromeos/login/auto_launched_kiosk_browsertest.cc
index 45408e1..98f5155 100644
--- a/chrome/browser/chromeos/login/auto_launched_kiosk_browsertest.cc
+++ b/chrome/browser/chromeos/login/auto_launched_kiosk_browsertest.cc
@@ -282,7 +282,7 @@
 
 }  // namespace
 
-class AutoLaunchedKioskTest : public ExtensionApiTest {
+class AutoLaunchedKioskTest : public extensions::ExtensionApiTest {
  public:
   AutoLaunchedKioskTest()
       : install_attributes_(
@@ -305,7 +305,7 @@
     ASSERT_TRUE(embedded_test_server()->InitializeAndListen());
     AppLaunchController::SkipSplashWaitForTesting();
 
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
@@ -314,7 +314,7 @@
     std::vector<std::string> secondary_apps = GetTestSecondaryAppIds();
     for (const auto& secondary_app : secondary_apps)
       fake_cws_->SetUpdateCrx(secondary_app, secondary_app + ".crx", "1.0.0");
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
   }
 
   bool SetUpUserDataDirectory() override {
@@ -352,7 +352,7 @@
     DBusThreadManager::GetSetterForTesting()->SetSessionManagerClient(
         std::move(fake_session_manager_));
 
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
   }
 
   void PreRunTestOnMainThread() override {
@@ -365,13 +365,13 @@
 
     embedded_test_server()->StartAcceptingConnections();
 
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
   }
 
   void TearDownOnMainThread() override {
     termination_observer_.reset();
 
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   void InitDevicePolicy() {
diff --git a/chrome/browser/chromeos/login/test/oobe_base_test.cc b/chrome/browser/chromeos/login/test/oobe_base_test.cc
index 094b8818..1b0ab0b 100644
--- a/chrome/browser/chromeos/login/test/oobe_base_test.cc
+++ b/chrome/browser/chromeos/login/test/oobe_base_test.cc
@@ -85,7 +85,7 @@
   // SetUpCommandLine().
   InitHttpsForwarders();
 
-  ExtensionApiTest::SetUp();
+  extensions::ExtensionApiTest::SetUp();
 }
 
 void OobeBaseTest::SetUpInProcessBrowserTestFixture() {
@@ -94,7 +94,7 @@
   network_portal_detector_->SetDefaultNetworkForTesting(
       FakeShillManagerClient::kFakeEthernetNetworkGuid);
 
-  ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+  extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
 }
 
 void OobeBaseTest::SetUpOnMainThread() {
@@ -128,17 +128,17 @@
     run_loop.Run();
   }
 
-  ExtensionApiTest::SetUpOnMainThread();
+  extensions::ExtensionApiTest::SetUpOnMainThread();
 }
 
 void OobeBaseTest::TearDownOnMainThread() {
   EXPECT_TRUE(embedded_test_server()->ShutdownAndWaitUntilComplete());
 
-  ExtensionApiTest::TearDownOnMainThread();
+  extensions::ExtensionApiTest::TearDownOnMainThread();
 }
 
 void OobeBaseTest::SetUpCommandLine(base::CommandLine* command_line) {
-  ExtensionApiTest::SetUpCommandLine(command_line);
+  extensions::ExtensionApiTest::SetUpCommandLine(command_line);
 
   command_line->AppendSwitch(ash::switches::kShowWebUiLogin);
   command_line->AppendSwitch(chromeos::switches::kLoginManager);
diff --git a/chrome/browser/chromeos/login/test/oobe_base_test.h b/chrome/browser/chromeos/login/test/oobe_base_test.h
index 397ad4a..f2e6092 100644
--- a/chrome/browser/chromeos/login/test/oobe_base_test.h
+++ b/chrome/browser/chromeos/login/test/oobe_base_test.h
@@ -34,7 +34,7 @@
 class NetworkPortalDetectorTestImpl;
 
 // Base class for OOBE, login, SAML and Kiosk tests.
-class OobeBaseTest : public ExtensionApiTest {
+class OobeBaseTest : public extensions::ExtensionApiTest {
  public:
   // Default fake user email and password, may be used by tests.
 
diff --git a/chrome/browser/devtools/devtools_sanity_browsertest.cc b/chrome/browser/devtools/devtools_sanity_browsertest.cc
index 075b517..4d76ded 100644
--- a/chrome/browser/devtools/devtools_sanity_browsertest.cc
+++ b/chrome/browser/devtools/devtools_sanity_browsertest.cc
@@ -1885,9 +1885,9 @@
       << "DevToolsAgentHost is not released when the tab is closed";
 }
 
-class RemoteDebuggingTest : public ExtensionApiTest {
+class RemoteDebuggingTest : public extensions::ExtensionApiTest {
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(switches::kRemoteDebuggingPort, "9222");
 
     // Override the extension root path.
diff --git a/chrome/browser/extensions/alert_apitest.cc b/chrome/browser/extensions/alert_apitest.cc
index 6415998..15c87ce 100644
--- a/chrome/browser/extensions/alert_apitest.cc
+++ b/chrome/browser/extensions/alert_apitest.cc
@@ -19,6 +19,8 @@
 #include "extensions/browser/process_manager.h"
 #include "extensions/common/extension.h"
 
+namespace extensions {
+
 namespace {
 
 void GetNextDialog(app_modal::NativeAppModalDialog** native_dialog) {
@@ -72,10 +74,9 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, AlertBasic) {
   ASSERT_TRUE(RunExtensionTest("alert")) << message_;
 
-  const extensions::Extension* extension = GetSingleLoadedExtension();
-  extensions::ExtensionHost* host =
-      extensions::ProcessManager::Get(browser()->profile())
-          ->GetBackgroundHostForExtension(extension->id());
+  const Extension* extension = GetSingleLoadedExtension();
+  ExtensionHost* host = ProcessManager::Get(browser()->profile())
+                            ->GetBackgroundHostForExtension(extension->id());
   ASSERT_TRUE(host);
   host->host_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
       base::ASCIIToUTF16("alert('This should not crash.');"));
@@ -86,10 +87,9 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, AlertQueue) {
   ASSERT_TRUE(RunExtensionTest("alert")) << message_;
 
-  const extensions::Extension* extension = GetSingleLoadedExtension();
-  extensions::ExtensionHost* host =
-      extensions::ProcessManager::Get(browser()->profile())
-          ->GetBackgroundHostForExtension(extension->id());
+  const Extension* extension = GetSingleLoadedExtension();
+  ExtensionHost* host = ProcessManager::Get(browser()->profile())
+                            ->GetBackgroundHostForExtension(extension->id());
   ASSERT_TRUE(host);
 
   // Creates several dialogs at the same time.
@@ -121,10 +121,9 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, ConfirmQueue) {
   ASSERT_TRUE(RunExtensionTest("alert")) << message_;
 
-  const extensions::Extension* extension = GetSingleLoadedExtension();
-  extensions::ExtensionHost* host =
-      extensions::ProcessManager::Get(browser()->profile())
-          ->GetBackgroundHostForExtension(extension->id());
+  const Extension* extension = GetSingleLoadedExtension();
+  ExtensionHost* host = ProcessManager::Get(browser()->profile())
+                            ->GetBackgroundHostForExtension(extension->id());
   ASSERT_TRUE(host);
 
   // Creates several dialogs at the same time.
@@ -163,3 +162,5 @@
   while (call_count < num_accepted_dialogs + num_cancelled_dialogs)
     ASSERT_NO_FATAL_FAILURE(content::RunAllPendingInMessageLoop());
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/autotest_private/autotest_private_apitest.cc b/chrome/browser/extensions/api/autotest_private/autotest_private_apitest.cc
index 3442d293..e1bd15e7f 100644
--- a/chrome/browser/extensions/api/autotest_private/autotest_private_apitest.cc
+++ b/chrome/browser/extensions/api/autotest_private/autotest_private_apitest.cc
@@ -6,12 +6,16 @@
 #include "chrome/browser/extensions/api/autotest_private/autotest_private_api.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 #if defined(OS_CHROMEOS)
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, AutotestPrivate) {
   // Turn on testing mode so we don't kill the browser.
-  extensions::AutotestPrivateAPI::GetFactoryInstance()
+  AutotestPrivateAPI::GetFactoryInstance()
       ->Get(browser()->profile())
       ->set_test_mode(true);
   ASSERT_TRUE(RunComponentExtensionTest("autotest_private")) << message_;
 }
 #endif
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_apitest.cc b/chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_apitest.cc
index 1b40c82..7d50faf 100644
--- a/chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_apitest.cc
+++ b/chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_apitest.cc
@@ -98,14 +98,14 @@
 const char kTestDescriptorUuid1[] = "1222";
 const uint8_t kTestDescriptorDefaultValue1[] = {0x04, 0x05};
 
-class BluetoothLowEnergyApiTest : public ExtensionApiTest {
+class BluetoothLowEnergyApiTest : public extensions::ExtensionApiTest {
  public:
   BluetoothLowEnergyApiTest() {}
 
   ~BluetoothLowEnergyApiTest() override {}
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     empty_extension_ = extensions::ExtensionBuilder("Test").Build();
     SetUpMocks();
   }
diff --git a/chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_apitest.cc b/chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_apitest.cc
index 35c4ad6..ad4ac598 100644
--- a/chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_apitest.cc
+++ b/chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_apitest.cc
@@ -26,6 +26,8 @@
 using bookmarks::BookmarkModel;
 using bookmarks::BookmarkNode;
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, BookmarkManager) {
   // Add managed bookmarks.
   Profile* profile = browser()->profile();
@@ -71,3 +73,5 @@
   ASSERT_TRUE(RunComponentExtensionTest("bookmark_manager/edit_disabled"))
       << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/bookmarks/bookmark_apitest.cc b/chrome/browser/extensions/api/bookmarks/bookmark_apitest.cc
index c4cdaf3..51335d49 100644
--- a/chrome/browser/extensions/api/bookmarks/bookmark_apitest.cc
+++ b/chrome/browser/extensions/api/bookmarks/bookmark_apitest.cc
@@ -21,6 +21,8 @@
 
 using bookmarks::BookmarkModel;
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Bookmarks) {
   // Add test managed bookmarks to verify that the bookmarks API can read them
   // and can't modify them.
@@ -44,3 +46,5 @@
 
   ASSERT_TRUE(RunExtensionTest("bookmarks")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/cast_streaming/performance_test.cc b/chrome/browser/extensions/api/cast_streaming/performance_test.cc
index 91d65b3..4f627788 100644
--- a/chrome/browser/extensions/api/cast_streaming/performance_test.cc
+++ b/chrome/browser/extensions/api/cast_streaming/performance_test.cc
@@ -345,9 +345,8 @@
   DISALLOW_COPY_AND_ASSIGN(TestPatternReceiver);
 };
 
-class CastV2PerformanceTest
-    : public ExtensionApiTest,
-      public testing::WithParamInterface<int> {
+class CastV2PerformanceTest : public extensions::ExtensionApiTest,
+                              public testing::WithParamInterface<int> {
  public:
   CastV2PerformanceTest() {}
 
@@ -401,7 +400,7 @@
     EnablePixelOutput();
     if (!HasFlag(kUseGpu))
       UseSoftwareCompositing();
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
@@ -424,7 +423,7 @@
         extensions::switches::kWhitelistedExtensionID,
         kExtensionId);
 
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
   }
 
   void GetTraceEvents(trace_analyzer::TraceAnalyzer* analyzer,
diff --git a/chrome/browser/extensions/api/certificate_provider/certificate_provider_apitest.cc b/chrome/browser/extensions/api/certificate_provider/certificate_provider_apitest.cc
index 01671bd64..62ab1ea 100644
--- a/chrome/browser/extensions/api/certificate_provider/certificate_provider_apitest.cc
+++ b/chrome/browser/extensions/api/certificate_provider/certificate_provider_apitest.cc
@@ -143,7 +143,7 @@
   EXPECT_EQ(SK_ColorRED, view->error_label_for_testing()->enabled_color());
 }
 
-class CertificateProviderApiTest : public ExtensionApiTest {
+class CertificateProviderApiTest : public extensions::ExtensionApiTest {
  public:
   CertificateProviderApiTest() {}
 
@@ -152,11 +152,11 @@
         .WillRepeatedly(Return(true));
     policy::BrowserPolicyConnector::SetPolicyProviderForTesting(&provider_);
 
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     // Set up the AutoSelectCertificateForUrls policy to avoid the client
     // certificate selection dialog.
     const std::string autoselect_pattern =
diff --git a/chrome/browser/extensions/api/cloud_print_private/cloud_print_private_apitest.cc b/chrome/browser/extensions/api/cloud_print_private/cloud_print_private_apitest.cc
index 7145f7c..a00d71d 100644
--- a/chrome/browser/extensions/api/cloud_print_private/cloud_print_private_apitest.cc
+++ b/chrome/browser/extensions/api/cloud_print_private/cloud_print_private_apitest.cc
@@ -22,10 +22,10 @@
 using ::testing::_;
 
 // A base class for tests below.
-class ExtensionCloudPrintPrivateApiTest : public ExtensionApiTest {
+class ExtensionCloudPrintPrivateApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         switches::kCloudPrintURL,
         "http://www.cloudprintapp.com/extensions/api_test/"
@@ -33,7 +33,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     // Start up the test server and get us ready for calling the install
     // API functions.
     host_resolver()->AddRule("www.cloudprintapp.com", "127.0.0.1");
diff --git a/chrome/browser/extensions/api/command_line_private/command_line_private_apitest.cc b/chrome/browser/extensions/api/command_line_private/command_line_private_apitest.cc
index 36de0ce..cdbd1f1 100644
--- a/chrome/browser/extensions/api/command_line_private/command_line_private_apitest.cc
+++ b/chrome/browser/extensions/api/command_line_private/command_line_private_apitest.cc
@@ -11,9 +11,9 @@
 const char kTestCommandLineSwitch[] = "command-line-private-api-test-foo";
 }  // namespace
 
-class CommandLinePrivateApiTest : public ExtensionApiTest {
+class CommandLinePrivateApiTest : public extensions::ExtensionApiTest {
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(kTestCommandLineSwitch);
   }
 };
diff --git a/chrome/browser/extensions/api/debugger/debugger_extension_apitest.cc b/chrome/browser/extensions/api/debugger/debugger_extension_apitest.cc
index a8a3ef89..efdbfbeb 100644
--- a/chrome/browser/extensions/api/debugger/debugger_extension_apitest.cc
+++ b/chrome/browser/extensions/api/debugger/debugger_extension_apitest.cc
@@ -7,10 +7,10 @@
 #include "chrome/common/chrome_switches.h"
 #include "extensions/common/switches.h"
 
-class ExtensionApiTestWithSwitch : public ExtensionApiTest {
+class ExtensionApiTestWithSwitch : public extensions::ExtensionApiTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(switches::kSilentDebuggerExtensionAPI);
     command_line->AppendSwitch(extensions::switches::kExtensionsOnChromeURLs);
   }
diff --git a/chrome/browser/extensions/api/declarative_net_request/declarative_net_request_apitest.cc b/chrome/browser/extensions/api/declarative_net_request/declarative_net_request_apitest.cc
index e46d400..97ade6a 100644
--- a/chrome/browser/extensions/api/declarative_net_request/declarative_net_request_apitest.cc
+++ b/chrome/browser/extensions/api/declarative_net_request/declarative_net_request_apitest.cc
@@ -12,14 +12,14 @@
 
 namespace {
 
-class DeclarativeNetRequestAPItest : public ExtensionApiTest {
+class DeclarativeNetRequestAPItest : public extensions::ExtensionApiTest {
  public:
   DeclarativeNetRequestAPItest() {}
 
  protected:
   // ExtensionApiTest override.
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
 
     base::FilePath test_data_dir =
         test_data_dir_.AppendASCII("declarative_net_request");
diff --git a/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc b/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc
index 5e205458..0566fd88 100644
--- a/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc
+++ b/chrome/browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_apitest_nss.cc
@@ -26,6 +26,8 @@
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace extensions {
+
 namespace {
 
 // The test extension has a certificate referencing this private key which will
@@ -191,8 +193,7 @@
                policy::POLICY_SOURCE_CLOUD, std::move(forcelist), nullptr);
 
     // Set the policy and wait until the extension is installed.
-    extensions::TestExtensionRegistryObserver observer(
-        extensions::ExtensionRegistry::Get(profile()));
+    TestExtensionRegistryObserver observer(ExtensionRegistry::Get(profile()));
     mock_policy_provider()->UpdateChromePolicy(policy);
     observer.WaitForExtensionWillBeInstalled();
   }
@@ -269,9 +270,6 @@
                PlatformKeysTestBase::EnrollmentStatus::ENROLLED,
                PlatformKeysTestBase::UserStatus::MANAGED_AFFILIATED_DOMAIN)));
 
-class EnterprisePlatformKeysTestNonPolicyInstalledExtension
-    : public EnterprisePlatformKeysTest {};
-
 // Ensure that extensions that are not pre-installed by policy throw an install
 // warning if they request the enterprise.platformKeys permission in the
 // manifest and that such extensions don't see the
@@ -284,9 +282,8 @@
 
   base::FilePath extension_path =
       test_data_dir_.AppendASCII("enterprise_platform_keys");
-  extensions::ExtensionRegistry* registry =
-      extensions::ExtensionRegistry::Get(profile());
-  const extensions::Extension* extension =
+  ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
+  const Extension* extension =
       GetExtensionByPath(registry->enabled_extensions(), extension_path);
   ASSERT_FALSE(extension->install_warnings().empty());
   EXPECT_EQ(
@@ -294,3 +291,5 @@
       "location.",
       extension->install_warnings()[0].message);
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/font_settings/font_settings_apitest.cc b/chrome/browser/extensions/api/font_settings/font_settings_apitest.cc
index 6e0fc6f..603f84f 100644
--- a/chrome/browser/extensions/api/font_settings/font_settings_apitest.cc
+++ b/chrome/browser/extensions/api/font_settings/font_settings_apitest.cc
@@ -11,6 +11,8 @@
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
 
+namespace extensions {
+
 // Test of extension API on a standard profile.
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, FontSettings) {
   PrefService* prefs = browser()->profile()->GetPrefs();
@@ -36,3 +38,5 @@
                                   "launch.html",
                                   flags));
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/i18n/i18n_apitest.cc b/chrome/browser/extensions/api/i18n/i18n_apitest.cc
index 6eda361..b8d0b5b 100644
--- a/chrome/browser/extensions/api/i18n/i18n_apitest.cc
+++ b/chrome/browser/extensions/api/i18n/i18n_apitest.cc
@@ -14,6 +14,8 @@
 #include "extensions/test/result_catcher.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, I18N) {
   ASSERT_TRUE(StartEmbeddedTestServer());
   ASSERT_TRUE(RunExtensionTest("i18n")) << message_;
@@ -35,10 +37,9 @@
       test_data_dir_.AppendASCII("i18nUpdate").AppendASCII("_locales"),
       extension_dir.GetPath().AppendASCII("_locales"), true);
 
-  const extensions::Extension* extension =
-      LoadExtension(extension_dir.GetPath());
+  const Extension* extension = LoadExtension(extension_dir.GetPath());
 
-  extensions::ResultCatcher catcher;
+  ResultCatcher catcher;
 
   // Test that the messages.json file is loaded and the i18n message is loaded.
   ui_test_utils::NavigateToURL(
@@ -65,3 +66,5 @@
   ui_test_utils::GetCurrentTabTitle(browser(), &title);
   EXPECT_EQ(std::string("SECONDMESSAGE"), base::UTF16ToUTF8(title));
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/identity/identity_apitest.cc b/chrome/browser/extensions/api/identity/identity_apitest.cc
index 8b5c6e49..3091e73 100644
--- a/chrome/browser/extensions/api/identity/identity_apitest.cc
+++ b/chrome/browser/extensions/api/identity/identity_apitest.cc
@@ -2372,9 +2372,9 @@
   EXPECT_FALSE(HasExpectedEvent());
 }
 
-}  // namespace extensions
-
 // Tests the chrome.identity API implemented by custom JS bindings .
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, ChromeIdentityJsBindings) {
   ASSERT_TRUE(RunExtensionTest("identity/js_bindings")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/idltest/idltest_apitest.cc b/chrome/browser/extensions/api/idltest/idltest_apitest.cc
index a81cb23..2329c87 100644
--- a/chrome/browser/extensions/api/idltest/idltest_apitest.cc
+++ b/chrome/browser/extensions/api/idltest/idltest_apitest.cc
@@ -7,7 +7,7 @@
 #include "extensions/common/features/feature_channel.h"
 #include "extensions/common/switches.h"
 
-class ExtensionIdltestApiTest : public ExtensionApiTest {
+class ExtensionIdltestApiTest : public extensions::ExtensionApiTest {
  public:
   // Set the channel to "trunk" since idltest is restricted to trunk.
   ExtensionIdltestApiTest() : trunk_(version_info::Channel::UNKNOWN) {}
diff --git a/chrome/browser/extensions/api/input_ime/input_ime_apitest_chromeos.cc b/chrome/browser/extensions/api/input_ime/input_ime_apitest_chromeos.cc
index af200ce..01b8c20 100644
--- a/chrome/browser/extensions/api/input_ime/input_ime_apitest_chromeos.cc
+++ b/chrome/browser/extensions/api/input_ime/input_ime_apitest_chromeos.cc
@@ -8,8 +8,12 @@
 #include "extensions/browser/api/test/test_api.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace extensions {
+
 #if defined(OS_CHROMEOS)
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, InputImeApiBasic) {
   ASSERT_TRUE(RunExtensionTest("input_ime")) << message_;
 }
 #endif
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/management/management_apitest.cc b/chrome/browser/extensions/api/management/management_apitest.cc
index 3a914ec3..2e470f69 100644
--- a/chrome/browser/extensions/api/management/management_apitest.cc
+++ b/chrome/browser/extensions/api/management/management_apitest.cc
@@ -42,7 +42,7 @@
 
 }  // namespace
 
-class ExtensionManagementApiTest : public ExtensionApiTest {
+class ExtensionManagementApiTest : public extensions::ExtensionApiTest {
  public:
   virtual void LoadExtensions() {
     base::FilePath basedir = test_data_dir_.AppendASCII("management");
diff --git a/chrome/browser/extensions/api/mdns/mdns_apitest.cc b/chrome/browser/extensions/api/mdns/mdns_apitest.cc
index 48bcf21..7751cef 100644
--- a/chrome/browser/extensions/api/mdns/mdns_apitest.cc
+++ b/chrome/browser/extensions/api/mdns/mdns_apitest.cc
@@ -23,12 +23,12 @@
 
 namespace {
 
-class MDnsAPITest : public ExtensionApiTest {
+class MDnsAPITest : public extensions::ExtensionApiTest {
  public:
   MDnsAPITest() {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         "ddchlicdkolnonkihahngkmmmjnjlkkf");
diff --git a/chrome/browser/extensions/api/media_galleries/media_galleries_watch_apitest.cc b/chrome/browser/extensions/api/media_galleries/media_galleries_watch_apitest.cc
index 0e662e5..f3a7613f 100644
--- a/chrome/browser/extensions/api/media_galleries/media_galleries_watch_apitest.cc
+++ b/chrome/browser/extensions/api/media_galleries/media_galleries_watch_apitest.cc
@@ -69,7 +69,7 @@
 //                 MediaGalleriesGalleryWatchApiTest                         //
 ///////////////////////////////////////////////////////////////////////////////
 
-class MediaGalleriesGalleryWatchApiTest : public ExtensionApiTest {
+class MediaGalleriesGalleryWatchApiTest : public extensions::ExtensionApiTest {
  public:
   MediaGalleriesGalleryWatchApiTest()
       : extension_(NULL), background_host_(NULL) {}
@@ -78,12 +78,12 @@
  protected:
   // ExtensionApiTest overrides.
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID, kTestExtensionId);
   }
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     ensure_media_directories_exists_.reset(new EnsureMediaDirectoriesExists);
     extension_ = LoadExtension(test_data_dir_.AppendASCII(kTestExtensionPath));
     GetBackgroundHostForTestExtension();
@@ -94,7 +94,7 @@
     extension_ = NULL;
     background_host_ = NULL;
     ensure_media_directories_exists_.reset();
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   bool GalleryWatchesSupported() {
diff --git a/chrome/browser/extensions/api/messaging/native_messaging_apitest.cc b/chrome/browser/extensions/api/messaging/native_messaging_apitest.cc
index eac88e8..0983cc2 100644
--- a/chrome/browser/extensions/api/messaging/native_messaging_apitest.cc
+++ b/chrome/browser/extensions/api/messaging/native_messaging_apitest.cc
@@ -5,6 +5,8 @@
 #include "chrome/browser/extensions/api/messaging/native_messaging_test_util.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, NativeMessagingBasic) {
   extensions::ScopedTestNativeMessagingHost test_host;
   ASSERT_NO_FATAL_FAILURE(test_host.RegisterTestHost(false));
@@ -16,3 +18,5 @@
   ASSERT_NO_FATAL_FAILURE(test_host.RegisterTestHost(true));
   ASSERT_TRUE(RunExtensionTest("native_messaging")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/metrics_private/metrics_apitest.cc b/chrome/browser/extensions/api/metrics_private/metrics_apitest.cc
index b41a3e1..c9862e8 100644
--- a/chrome/browser/extensions/api/metrics_private/metrics_apitest.cc
+++ b/chrome/browser/extensions/api/metrics_private/metrics_apitest.cc
@@ -14,6 +14,8 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "components/variations/variations_associated_data.h"
 
+namespace extensions {
+
 namespace {
 
 // The tests that are run by this extension are expected to record the following
@@ -126,7 +128,7 @@
   }
 }
 
-}  // anonymous namespace
+}  // namespace
 
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Metrics) {
   base::UserActionTester user_action_tester;
@@ -145,3 +147,5 @@
                       arraysize(g_user_actions));
   ValidateHistograms(g_histograms, arraysize(g_histograms));
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/module/module_apitest.cc b/chrome/browser/extensions/api/module/module_apitest.cc
index 748b132..ca037e4 100644
--- a/chrome/browser/extensions/api/module/module_apitest.cc
+++ b/chrome/browser/extensions/api/module/module_apitest.cc
@@ -4,8 +4,7 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
-class ExtensionModuleApiTest : public ExtensionApiTest {
-};
+using ExtensionModuleApiTest = extensions::ExtensionApiTest;
 
 IN_PROC_BROWSER_TEST_F(ExtensionModuleApiTest, CognitoFile) {
   ASSERT_TRUE(RunExtensionTest("extension_module/cognito_file")) << message_;
diff --git a/chrome/browser/extensions/api/networking_config_chromeos_apitest_chromeos.cc b/chrome/browser/extensions/api/networking_config_chromeos_apitest_chromeos.cc
index 49a11dfa..4cfa0b9 100644
--- a/chrome/browser/extensions/api/networking_config_chromeos_apitest_chromeos.cc
+++ b/chrome/browser/extensions/api/networking_config_chromeos_apitest_chromeos.cc
@@ -46,14 +46,14 @@
 }  // namespace
 
 class NetworkingConfigTest
-    : public ExtensionApiTest,
+    : public extensions::ExtensionApiTest,
       public captive_portal::CaptivePortalDetectorTestBase {
  public:
   NetworkingConfigTest() : network_portal_detector_(nullptr) {}
   ~NetworkingConfigTest() override = default;
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     content::RunAllPendingInMessageLoop();
 
     display_service_ = std::make_unique<NotificationDisplayServiceTester>(
diff --git a/chrome/browser/extensions/api/networking_private/networking_private_chromeos_apitest.cc b/chrome/browser/extensions/api/networking_private/networking_private_chromeos_apitest.cc
index 991d90c..475010d 100644
--- a/chrome/browser/extensions/api/networking_private/networking_private_chromeos_apitest.cc
+++ b/chrome/browser/extensions/api/networking_private/networking_private_chromeos_apitest.cc
@@ -187,7 +187,7 @@
   DISALLOW_COPY_AND_ASSIGN(TestListener);
 };
 
-class NetworkingPrivateChromeOSApiTest : public ExtensionApiTest {
+class NetworkingPrivateChromeOSApiTest : public extensions::ExtensionApiTest {
  public:
   NetworkingPrivateChromeOSApiTest()
       : detector_(nullptr),
@@ -208,11 +208,11 @@
         .WillRepeatedly(Return(true));
     policy::BrowserPolicyConnector::SetPolicyProviderForTesting(&provider_);
 
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     // Whitelist the extension ID of the test extension.
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
@@ -345,14 +345,14 @@
     ChromeNetworkingCastPrivateDelegate::SetFactoryCallbackForTest(
         &networking_cast_delegate_factory_);
 
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpOnMainThread() override {
     detector_ = new NetworkPortalDetectorTestImpl();
     chromeos::network_portal_detector::InitializeForTesting(detector_);
 
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     content::RunAllPendingInMessageLoop();
 
     NetworkingPrivateDelegateFactory::GetInstance()->SetTestingFactory(
@@ -485,7 +485,7 @@
   }
 
   void TearDown() override {
-    ExtensionApiTest::TearDown();
+    extensions::ExtensionApiTest::TearDown();
     ChromeNetworkingCastPrivateDelegate::SetFactoryCallbackForTest(nullptr);
   }
 
diff --git a/chrome/browser/extensions/api/networking_private/networking_private_service_client_apitest.cc b/chrome/browser/extensions/api/networking_private/networking_private_service_client_apitest.cc
index 6b2b32b..12ca21e 100644
--- a/chrome/browser/extensions/api/networking_private/networking_private_service_client_apitest.cc
+++ b/chrome/browser/extensions/api/networking_private/networking_private_service_client_apitest.cc
@@ -91,7 +91,8 @@
   DISALLOW_COPY_AND_ASSIGN(TestNetworkingCastPrivateDelegate);
 };
 
-class NetworkingPrivateServiceClientApiTest : public ExtensionApiTest {
+class NetworkingPrivateServiceClientApiTest
+    : public extensions::ExtensionApiTest {
  public:
   NetworkingPrivateServiceClientApiTest() {}
 
@@ -102,7 +103,7 @@
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     // Whitelist the extension ID of the test extension.
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
@@ -124,11 +125,11 @@
                    base::Unretained(this));
     ChromeNetworkingCastPrivateDelegate::SetFactoryCallbackForTest(
         &networking_cast_delegate_factory_);
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     content::RunAllPendingInMessageLoop();
     NetworkingPrivateDelegateFactory::GetInstance()->SetTestingFactory(
         profile(), &CreateNetworkingPrivateServiceClient);
@@ -136,11 +137,11 @@
 
   void TearDownOnMainThread() override {
     content::RunAllPendingInMessageLoop();
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   void TearDown() override {
-    ExtensionApiTest::TearDown();
+    extensions::ExtensionApiTest::TearDown();
     ChromeNetworkingCastPrivateDelegate::SetFactoryCallbackForTest(nullptr);
   }
 
diff --git a/chrome/browser/extensions/api/notifications/notifications_apitest.cc b/chrome/browser/extensions/api/notifications/notifications_apitest.cc
index 8cf7c2c..fbca69e 100644
--- a/chrome/browser/extensions/api/notifications/notifications_apitest.cc
+++ b/chrome/browser/extensions/api/notifications/notifications_apitest.cc
@@ -111,7 +111,7 @@
   NORMAL
 };
 
-class NotificationsApiTest : public ExtensionApiTest {
+class NotificationsApiTest : public extensions::ExtensionApiTest {
  public:
   const Extension* LoadExtensionAndWait(
       const std::string& test_name) {
@@ -172,7 +172,7 @@
 
  protected:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
 
     DCHECK(profile());
     display_service_tester_ =
@@ -181,7 +181,7 @@
 
   void TearDownOnMainThread() override {
     display_service_tester_.reset();
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   // Returns the notification that's being displayed for |extension|, or nullptr
diff --git a/chrome/browser/extensions/api/omnibox/omnibox_api_testbase.h b/chrome/browser/extensions/api/omnibox/omnibox_api_testbase.h
index 0013aa0..c95e2c48 100644
--- a/chrome/browser/extensions/api/omnibox/omnibox_api_testbase.h
+++ b/chrome/browser/extensions/api/omnibox/omnibox_api_testbase.h
@@ -24,7 +24,7 @@
 
 class AutocompleteController;
 
-class OmniboxApiTest : public ExtensionApiTest {
+class OmniboxApiTest : public extensions::ExtensionApiTest {
  protected:
   LocationBar* GetLocationBar(Browser* browser) const {
     return browser->window()->GetLocationBar();
diff --git a/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc b/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc
index 3e7e9bd2..96e50f1b 100644
--- a/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc
+++ b/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc
@@ -22,14 +22,14 @@
 using extensions::PageCaptureSaveAsMHTMLFunction;
 using extensions::ScopedTestDialogAutoConfirm;
 
-class ExtensionPageCaptureApiTest : public ExtensionApiTest {
+class ExtensionPageCaptureApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(switches::kJavaScriptFlags, "--expose-gc");
   }
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
   }
 };
diff --git a/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.cc b/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.cc
index 1b3a6e9..24934f6a 100644
--- a/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.cc
+++ b/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.cc
@@ -72,11 +72,11 @@
       GaiaUrls::GetInstance()->gaia_url().host(),
       embedded_test_server()->base_url()));
 
-  ExtensionApiTest::SetUp();
+  extensions::ExtensionApiTest::SetUp();
 }
 
 void PlatformKeysTestBase::SetUpCommandLine(base::CommandLine* command_line) {
-  ExtensionApiTest::SetUpCommandLine(command_line);
+  extensions::ExtensionApiTest::SetUpCommandLine(command_line);
 
   policy::affiliation_test_helper::AppendCommandLineSwitchesForLoginManager(
       command_line);
@@ -91,7 +91,7 @@
 }
 
 void PlatformKeysTestBase::SetUpInProcessBrowserTestFixture() {
-  ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+  extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
 
   chromeos::FakeSessionManagerClient* fake_session_manager_client =
       new chromeos::FakeSessionManagerClient;
@@ -162,11 +162,11 @@
     loop.Run();
   }
 
-  ExtensionApiTest::SetUpOnMainThread();
+  extensions::ExtensionApiTest::SetUpOnMainThread();
 }
 
 void PlatformKeysTestBase::TearDownOnMainThread() {
-  ExtensionApiTest::TearDownOnMainThread();
+  extensions::ExtensionApiTest::TearDownOnMainThread();
 
   if (system_token_status() == SystemTokenStatus::EXISTS) {
     base::RunLoop loop;
diff --git a/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.h b/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.h
index 7d7eaf55..75f5259 100644
--- a/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.h
+++ b/chrome/browser/extensions/api/platform_keys/platform_keys_test_base.h
@@ -23,7 +23,7 @@
 // availability, device enrollment status, user affiliation and user policy.
 // Every test case is supposed to have a PRE_ test case which must call
 // PlatformKeysTestBase::RunPreTest.
-class PlatformKeysTestBase : public ExtensionApiTest {
+class PlatformKeysTestBase : public extensions::ExtensionApiTest {
  public:
   enum class SystemTokenStatus { EXISTS, DOES_NOT_EXIST };
 
diff --git a/chrome/browser/extensions/api/preference/preference_apitest.cc b/chrome/browser/extensions/api/preference/preference_apitest.cc
index 17b0bfd..0cbda89 100644
--- a/chrome/browser/extensions/api/preference/preference_apitest.cc
+++ b/chrome/browser/extensions/api/preference/preference_apitest.cc
@@ -35,7 +35,7 @@
 #include "extensions/test/result_catcher.h"
 #include "media/media_buildflags.h"
 
-class ExtensionPreferenceApiTest : public ExtensionApiTest {
+class ExtensionPreferenceApiTest : public extensions::ExtensionApiTest {
  protected:
   ExtensionPreferenceApiTest() : profile_(NULL) {}
 
@@ -80,7 +80,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
 
     // The browser might get closed later (and therefore be destroyed), so we
     // save the profile.
@@ -101,7 +101,7 @@
                                   base::Unretained(&keep_alive_), nullptr));
     content::RunAllPendingInMessageLoop();
 
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   Profile* profile_;
diff --git a/chrome/browser/extensions/api/processes/processes_apitest.cc b/chrome/browser/extensions/api/processes/processes_apitest.cc
index da8e064..c470ed4 100644
--- a/chrome/browser/extensions/api/processes/processes_apitest.cc
+++ b/chrome/browser/extensions/api/processes/processes_apitest.cc
@@ -13,7 +13,7 @@
 #include "extensions/common/switches.h"
 #include "extensions/test/extension_test_message_listener.h"
 
-class ProcessesApiTest : public ExtensionApiTest {
+class ProcessesApiTest : public extensions::ExtensionApiTest {
  public:
   ProcessesApiTest() {}
   ~ProcessesApiTest() override {}
diff --git a/chrome/browser/extensions/api/resources_private/resources_private_apitest.cc b/chrome/browser/extensions/api/resources_private/resources_private_apitest.cc
index 9b8b16c1..bddf8cd 100644
--- a/chrome/browser/extensions/api/resources_private/resources_private_apitest.cc
+++ b/chrome/browser/extensions/api/resources_private/resources_private_apitest.cc
@@ -5,13 +5,7 @@
 #include "base/macros.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 
-class ResourcesPrivateApiTest : public ExtensionApiTest {
- public:
-  ResourcesPrivateApiTest() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ResourcesPrivateApiTest);
-};
+using ResourcesPrivateApiTest = extensions::ExtensionApiTest;
 
 IN_PROC_BROWSER_TEST_F(ResourcesPrivateApiTest, GetStrings) {
   ASSERT_TRUE(RunComponentExtensionTest("resources_private/get_strings"));
diff --git a/chrome/browser/extensions/api/runtime/runtime_apitest.cc b/chrome/browser/extensions/api/runtime/runtime_apitest.cc
index a1f7840..b26ef11 100644
--- a/chrome/browser/extensions/api/runtime/runtime_apitest.cc
+++ b/chrome/browser/extensions/api/runtime/runtime_apitest.cc
@@ -20,6 +20,8 @@
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "url/url_constants.h"
 
+namespace extensions {
+
 // Tests the privileged components of chrome.runtime.
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, ChromeRuntimePrivileged) {
   ASSERT_TRUE(RunExtensionTest("runtime/privileged")) << message_;
@@ -48,8 +50,6 @@
   ASSERT_TRUE(RunExtensionTest("runtime/uninstall_url")) << message_;
 }
 
-namespace extensions {
-
 namespace {
 
 const char kUninstallUrl[] = "http://www.google.com/";
diff --git a/chrome/browser/extensions/api/socket/socket_apitest.cc b/chrome/browser/extensions/api/socket/socket_apitest.cc
index b171049..ae11686 100644
--- a/chrome/browser/extensions/api/socket/socket_apitest.cc
+++ b/chrome/browser/extensions/api/socket/socket_apitest.cc
@@ -25,7 +25,7 @@
 const char kHostname[] = "127.0.0.1";
 const int kPort = 8888;
 
-class SocketApiTest : public ExtensionApiTest {
+class SocketApiTest : public extensions::ExtensionApiTest {
  public:
   SocketApiTest()
       : resolver_event_(base::WaitableEvent::ResetPolicy::MANUAL,
@@ -33,7 +33,7 @@
         resolver_creator_(new extensions::MockHostResolverCreator()) {}
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     extensions::HostResolverWrapper::GetInstance()->SetHostResolverForTesting(
         resolver_creator_->CreateMockHostResolver());
   }
diff --git a/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc b/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc
index 7384bff..dc572510 100644
--- a/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc
+++ b/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc
@@ -131,7 +131,7 @@
 // The test extension expects the resources that should be handed to the
 // extension to have MIME type 'application/msword' and the resources that
 // should be downloaded by the browser to have MIME type 'text/plain'.
-class StreamsPrivateApiTest : public ExtensionApiTest {
+class StreamsPrivateApiTest : public extensions::ExtensionApiTest {
  public:
   StreamsPrivateApiTest() {}
 
@@ -143,14 +143,14 @@
     test_server_->RegisterRequestHandler(base::Bind(&HandleRequest));
     ASSERT_TRUE(test_server_->Start());
     host_resolver()->AddRule("*", "127.0.0.1");
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
   }
 
   void TearDownOnMainThread() override {
     // Tear down the test server.
     EXPECT_TRUE(test_server_->ShutdownAndWaitUntilComplete());
     test_server_.reset();
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   void InitializeDownloadSettings() {
diff --git a/chrome/browser/extensions/api/sync_file_system/sync_file_system_apitest.cc b/chrome/browser/extensions/api/sync_file_system/sync_file_system_apitest.cc
index b8f1c6b..7117b06 100644
--- a/chrome/browser/extensions/api/sync_file_system/sync_file_system_apitest.cc
+++ b/chrome/browser/extensions/api/sync_file_system/sync_file_system_apitest.cc
@@ -37,14 +37,14 @@
 
 namespace {
 
-class SyncFileSystemApiTest : public ExtensionApiTest {
+class SyncFileSystemApiTest : public extensions::ExtensionApiTest {
  public:
   SyncFileSystemApiTest()
       : mock_remote_service_(NULL),
         real_default_quota_(0) {}
 
   void SetUpInProcessBrowserTestFixture() override {
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
 
     // TODO(calvinlo): Update test code after default quota is made const
     // (http://crbug.com/155488).
@@ -56,7 +56,7 @@
   void TearDownInProcessBrowserTestFixture() override {
     storage::QuotaManager::kSyncableStorageDefaultHostQuota =
         real_default_quota_;
-    ExtensionApiTest::TearDownInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::TearDownInProcessBrowserTestFixture();
   }
 
   void SetUpOnMainThread() override {
@@ -66,7 +66,7 @@
     mock_remote_service_ = new ::testing::NiceMock<MockRemoteFileSyncService>;
     SyncFileSystemServiceFactory::GetInstance()->set_mock_remote_file_service(
         std::unique_ptr<RemoteFileSyncService>(mock_remote_service_));
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
   }
 
   ::testing::NiceMock<MockRemoteFileSyncService>* mock_remote_service() {
diff --git a/chrome/browser/extensions/api/system_indicator/system_indicator_apitest.cc b/chrome/browser/extensions/api/system_indicator/system_indicator_apitest.cc
index a903caf..2313974 100644
--- a/chrome/browser/extensions/api/system_indicator/system_indicator_apitest.cc
+++ b/chrome/browser/extensions/api/system_indicator/system_indicator_apitest.cc
@@ -13,6 +13,8 @@
 #include "extensions/common/extension.h"
 #include "extensions/test/result_catcher.h"
 
+namespace extensions {
+
 class SystemIndicatorApiTest : public ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
@@ -65,3 +67,5 @@
     EXPECT_TRUE(catcher.GetNextResult()) << catcher.message();
   }
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/system_indicator/system_indicator_manager.h b/chrome/browser/extensions/api/system_indicator/system_indicator_manager.h
index 7604511..a16d5f37f 100644
--- a/chrome/browser/extensions/api/system_indicator/system_indicator_manager.h
+++ b/chrome/browser/extensions/api/system_indicator/system_indicator_manager.h
@@ -21,9 +21,9 @@
 class Profile;
 class StatusTray;
 
+namespace extensions {
 FORWARD_DECLARE_TEST(SystemIndicatorApiTest, SystemIndicator);
 
-namespace extensions {
 class ExtensionIndicatorIcon;
 class ExtensionRegistry;
 
@@ -41,7 +41,7 @@
   void Shutdown() override;
 
  private:
-  FRIEND_TEST_ALL_PREFIXES(::SystemIndicatorApiTest, SystemIndicator);
+  FRIEND_TEST_ALL_PREFIXES(SystemIndicatorApiTest, SystemIndicator);
 
   // ExtensionRegistryObserver implementation.
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
diff --git a/chrome/browser/extensions/api/system_private/system_private_apitest.cc b/chrome/browser/extensions/api/system_private/system_private_apitest.cc
index 6b47168d..6f14af1 100644
--- a/chrome/browser/extensions/api/system_private/system_private_apitest.cc
+++ b/chrome/browser/extensions/api/system_private/system_private_apitest.cc
@@ -17,6 +17,8 @@
 using chromeos::UpdateEngineClient;
 #endif
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, GetIncognitoModeAvailability) {
   PrefService* pref_service = browser()->profile()->GetPrefs();
   pref_service->SetInteger(prefs::kIncognitoModeAvailability, 1);
@@ -69,3 +71,5 @@
 }
 
 #endif
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/tab_capture/tab_capture_performancetest.cc b/chrome/browser/extensions/api/tab_capture/tab_capture_performancetest.cc
index 38e56a88..9aadd4d 100644
--- a/chrome/browser/extensions/api/tab_capture/tab_capture_performancetest.cc
+++ b/chrome/browser/extensions/api/tab_capture/tab_capture_performancetest.cc
@@ -49,9 +49,8 @@
   kSmallWindow = 1 << 4,         // Window size: 1 = 800x600, 0 = 2000x1000
 };
 
-class TabCapturePerformanceTest
-    : public ExtensionApiTest,
-      public testing::WithParamInterface<int> {
+class TabCapturePerformanceTest : public extensions::ExtensionApiTest,
+                                  public testing::WithParamInterface<int> {
  public:
   TabCapturePerformanceTest() {}
 
@@ -78,7 +77,7 @@
     EnablePixelOutput();
     if (!HasFlag(kUseGpu))
       UseSoftwareCompositing();
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
   }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
@@ -101,7 +100,7 @@
         extensions::switches::kWhitelistedExtensionID,
         kExtensionId);
 
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
   }
 
   void FindEvents(trace_analyzer::TraceAnalyzer* analyzer,
diff --git a/chrome/browser/extensions/api/terminal/terminal_private_apitest.cc b/chrome/browser/extensions/api/terminal/terminal_private_apitest.cc
index 7069e3d..f14022f 100644
--- a/chrome/browser/extensions/api/terminal/terminal_private_apitest.cc
+++ b/chrome/browser/extensions/api/terminal/terminal_private_apitest.cc
@@ -6,9 +6,9 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "extensions/common/switches.h"
 
-class ExtensionTerminalPrivateApiTest : public ExtensionApiTest {
+class ExtensionTerminalPrivateApiTest : public extensions::ExtensionApiTest {
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         "kidcpjlbjdmcnmccjhjdckhbngnhnepk");
diff --git a/chrome/browser/extensions/api/test/apitest_apitest.cc b/chrome/browser/extensions/api/test/apitest_apitest.cc
index 385a8d0..8f26f30f 100644
--- a/chrome/browser/extensions/api/test/apitest_apitest.cc
+++ b/chrome/browser/extensions/api/test/apitest_apitest.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, ApiTest) {
   ASSERT_TRUE(RunExtensionTest("apitest")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/api/vpn_provider/vpn_provider_apitest.cc b/chrome/browser/extensions/api/vpn_provider/vpn_provider_apitest.cc
index cd090aa..000c2d5 100644
--- a/chrome/browser/extensions/api/vpn_provider/vpn_provider_apitest.cc
+++ b/chrome/browser/extensions/api/vpn_provider/vpn_provider_apitest.cc
@@ -114,25 +114,25 @@
   std::vector<char> ip_packet_;
 };
 
-class VpnProviderApiTest : public ExtensionApiTest,
+class VpnProviderApiTest : public extensions::ExtensionApiTest,
                            public NetworkConfigurationObserver {
  public:
   VpnProviderApiTest() {}
   ~VpnProviderApiTest() override {}
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     NetworkHandler::Get()->network_configuration_handler()->AddObserver(this);
   }
 
   void TearDownOnMainThread() override {
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
     NetworkHandler::Get()->network_configuration_handler()->RemoveObserver(
         this);
   }
 
   void SetUpInProcessBrowserTestFixture() override {
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
     test_client_ = new TestShillThirdPartyVpnDriverClient();
     DBusThreadManager::GetSetterForTesting()->SetShillThirdPartyVpnDriverClient(
         base::WrapUnique(test_client_));
diff --git a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_apitest.cc b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_apitest.cc
index 3eb3499..c878060 100644
--- a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_apitest.cc
+++ b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_logging_private_apitest.cc
@@ -71,12 +71,12 @@
   parameters->Append(std::move(meta_data));
 }
 
-class WebrtcLoggingPrivateApiTest : public ExtensionApiTest {
+class WebrtcLoggingPrivateApiTest : public extensions::ExtensionApiTest {
  protected:
   void SetUp() override {
     auto* cl = scoped_command_line_.GetProcessCommandLine();
     cl->AppendSwitchASCII(::switches::kWebRtcRemoteEventLog, "enabled");
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
     extension_ = extensions::ExtensionBuilder("Test").Build();
   }
 
@@ -347,7 +347,7 @@
   void SetUp() override {
     auto* cl = scoped_command_line_.GetProcessCommandLine();
     cl->AppendSwitchASCII(::switches::kWebRtcRemoteEventLog, "disabled");
-    ExtensionApiTest::SetUp();
+    extensions::ExtensionApiTest::SetUp();
     extension_ = extensions::ExtensionBuilder("Test").Build();
   }
 };
diff --git a/chrome/browser/extensions/app_background_page_apitest.cc b/chrome/browser/extensions/app_background_page_apitest.cc
index df3de11..050e1c26 100644
--- a/chrome/browser/extensions/app_background_page_apitest.cc
+++ b/chrome/browser/extensions/app_background_page_apitest.cc
@@ -47,16 +47,16 @@
 
 using extensions::Extension;
 
-class AppBackgroundPageApiTest : public ExtensionApiTest {
+class AppBackgroundPageApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(switches::kDisablePopupBlocking);
     command_line->AppendSwitch(extensions::switches::kAllowHTTPBackgroundPage);
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
diff --git a/chrome/browser/extensions/app_process_apitest.cc b/chrome/browser/extensions/app_process_apitest.cc
index 0127c3d..790b275c 100644
--- a/chrome/browser/extensions/app_process_apitest.cc
+++ b/chrome/browser/extensions/app_process_apitest.cc
@@ -43,7 +43,7 @@
 using content::WebContents;
 using extensions::Extension;
 
-class AppApiTest : public ExtensionApiTest {
+class AppApiTest : public extensions::ExtensionApiTest {
  protected:
   // Gets the base URL for files for a specific test, making sure that it uses
   // "localhost" as the hostname, since that is what the extent is declared
@@ -58,7 +58,7 @@
 
   // Pass flags to make testing apps easier.
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kDisablePopupBlocking);
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
@@ -66,7 +66,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
@@ -145,7 +145,7 @@
 class BlockedAppApiTest : public AppApiTest {
  protected:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         extensions::switches::kAllowHTTPBackgroundPage);
   }
diff --git a/chrome/browser/extensions/autoplay_browsertest.cc b/chrome/browser/extensions/autoplay_browsertest.cc
index 6ac8d7b..6fadfc6a 100644
--- a/chrome/browser/extensions/autoplay_browsertest.cc
+++ b/chrome/browser/extensions/autoplay_browsertest.cc
@@ -13,10 +13,10 @@
 #include "extensions/test/test_extension_dir.h"
 #include "media/base/media_switches.h"
 
-class AutoplayExtensionBrowserTest : public ExtensionApiTest {
+class AutoplayExtensionBrowserTest : public extensions::ExtensionApiTest {
  public:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionBrowserTest::SetUpCommandLine(command_line);
+    extensions::ExtensionBrowserTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         switches::kAutoplayPolicy,
         switches::autoplay::kDocumentUserActivationRequiredPolicy);
diff --git a/chrome/browser/extensions/background_page_apitest.cc b/chrome/browser/extensions/background_page_apitest.cc
index d444983..e0ff85f8 100644
--- a/chrome/browser/extensions/background_page_apitest.cc
+++ b/chrome/browser/extensions/background_page_apitest.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Canvas2D) {
   ASSERT_TRUE(RunExtensionTest("canvas_2d")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/background_scripts_apitest.cc b/chrome/browser/extensions/background_scripts_apitest.cc
index 292f6bc..7440d83 100644
--- a/chrome/browser/extensions/background_scripts_apitest.cc
+++ b/chrome/browser/extensions/background_scripts_apitest.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, BackgroundScripts) {
   ASSERT_TRUE(RunExtensionTest("background_scripts")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/clipboard_extension_apitest_chromeos.cc b/chrome/browser/extensions/clipboard_extension_apitest_chromeos.cc
index cac85c95..d799a50e 100644
--- a/chrome/browser/extensions/clipboard_extension_apitest_chromeos.cc
+++ b/chrome/browser/extensions/clipboard_extension_apitest_chromeos.cc
@@ -5,11 +5,7 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "extensions/test/extension_test_message_listener.h"
 
-namespace {
-
-class ClipboardExtensionApiTest : public ExtensionApiTest {};
-
-}  // namespace
+using ClipboardExtensionApiTest = extensions::ExtensionApiTest;
 
 IN_PROC_BROWSER_TEST_F(ClipboardExtensionApiTest, ClipboardDataChanged) {
   ExtensionTestMessageListener result_listener("success 2", false);
diff --git a/chrome/browser/extensions/content_capabilities_browsertest.cc b/chrome/browser/extensions/content_capabilities_browsertest.cc
index 2b0875a..284be119 100644
--- a/chrome/browser/extensions/content_capabilities_browsertest.cc
+++ b/chrome/browser/extensions/content_capabilities_browsertest.cc
@@ -35,10 +35,10 @@
 using extensions::ExtensionBuilder;
 using extensions::ListBuilder;
 
-class ContentCapabilitiesTest : public ExtensionApiTest {
+class ContentCapabilitiesTest : public extensions::ExtensionApiTest {
  protected:
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         crx_file::id_util::GenerateIdForPath(
@@ -46,7 +46,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     base::FilePath test_data;
     EXPECT_TRUE(base::PathService::Get(chrome::DIR_TEST_DATA, &test_data));
     embedded_test_server()->ServeFilesFromDirectory(
diff --git a/chrome/browser/extensions/content_security_policy_apitest.cc b/chrome/browser/extensions/content_security_policy_apitest.cc
index cbf104d..0d611072 100644
--- a/chrome/browser/extensions/content_security_policy_apitest.cc
+++ b/chrome/browser/extensions/content_security_policy_apitest.cc
@@ -6,6 +6,8 @@
 #include "chrome/common/chrome_switches.h"
 #include "net/dns/mock_host_resolver.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, ContentSecurityPolicy) {
   ASSERT_TRUE(StartEmbeddedTestServer());
   ASSERT_TRUE(RunExtensionTest("content_security_policy")) << message_;
@@ -16,3 +18,5 @@
   ASSERT_TRUE(RunExtensionTest("default_content_security_policy")) <<
       message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/cross_origin_xhr_apitest.cc b/chrome/browser/extensions/cross_origin_xhr_apitest.cc
index a9bc130..05c9696 100644
--- a/chrome/browser/extensions/cross_origin_xhr_apitest.cc
+++ b/chrome/browser/extensions/cross_origin_xhr_apitest.cc
@@ -8,10 +8,10 @@
 const base::FilePath::CharType kFtpDocRoot[] =
     FILE_PATH_LITERAL("chrome/test/data");
 
-class CrossOriginXHR : public ExtensionApiTest {
+class CrossOriginXHR : public extensions::ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*.com", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
diff --git a/chrome/browser/extensions/execute_script_apitest.cc b/chrome/browser/extensions/execute_script_apitest.cc
index 9f4f6efc..3daac23 100644
--- a/chrome/browser/extensions/execute_script_apitest.cc
+++ b/chrome/browser/extensions/execute_script_apitest.cc
@@ -9,10 +9,10 @@
 #include "net/base/filename_util.h"
 #include "net/dns/mock_host_resolver.h"
 
-class ExecuteScriptApiTest : public ExtensionApiTest {
+class ExecuteScriptApiTest : public extensions::ExtensionApiTest {
  protected:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     // We need a.com to be a little bit slow to trigger a race condition.
     host_resolver()->AddRuleWithLatency("a.com", "127.0.0.1", 500);
     host_resolver()->AddRule("*", "127.0.0.1");
diff --git a/chrome/browser/extensions/extension_apitest.cc b/chrome/browser/extensions/extension_apitest.cc
index 91b49fe..3b9c979 100644
--- a/chrome/browser/extensions/extension_apitest.cc
+++ b/chrome/browser/extensions/extension_apitest.cc
@@ -41,9 +41,9 @@
 #include "net/test/embedded_test_server/http_response.h"
 #include "net/test/spawned_test_server/spawned_test_server.h"
 
-namespace {
+namespace extensions {
 
-using extensions::ExtensionBrowserTest;
+namespace {
 
 const char kTestCustomArg[] = "customArg";
 const char kTestDataDirectory[] = "testDataDirectory";
@@ -172,14 +172,13 @@
   }
   test_config_->SetBoolean(
       kNativeCrxBindingsEnabled,
-      base::FeatureList::IsEnabled(extensions::features::kNativeCrxBindings));
-  extensions::TestGetConfigFunction::set_test_config_state(
-      test_config_.get());
+      base::FeatureList::IsEnabled(features::kNativeCrxBindings));
+  TestGetConfigFunction::set_test_config_state(test_config_.get());
 }
 
 void ExtensionApiTest::TearDownOnMainThread() {
   ExtensionBrowserTest::TearDownOnMainThread();
-  extensions::TestGetConfigFunction::set_test_config_state(NULL);
+  TestGetConfigFunction::set_test_config_state(NULL);
   test_config_.reset(NULL);
 }
 
@@ -333,11 +332,11 @@
   if (custom_arg && custom_arg[0])
     SetCustomArg(custom_arg);
 
-  extensions::ResultCatcher catcher;
+  ResultCatcher catcher;
   DCHECK(!extension_name.empty() || !page_url.empty()) <<
       "extension_name and page_url cannot both be empty";
 
-  const extensions::Extension* extension = NULL;
+  const Extension* extension = NULL;
   if (!extension_name.empty()) {
     const base::FilePath& root_path =
         use_root_extensions_dir ? shared_test_data_dir_ : test_data_dir_;
@@ -383,9 +382,9 @@
     else
       ui_test_utils::NavigateToURL(browser(), url);
   } else if (launch_platform_app) {
-    AppLaunchParams params(
-        browser()->profile(), extension, extensions::LAUNCH_CONTAINER_NONE,
-        WindowOpenDisposition::NEW_WINDOW, extensions::SOURCE_TEST);
+    AppLaunchParams params(browser()->profile(), extension,
+                           LAUNCH_CONTAINER_NONE,
+                           WindowOpenDisposition::NEW_WINDOW, SOURCE_TEST);
     params.command_line = *base::CommandLine::ForCurrentProcess();
     OpenApplication(params);
   }
@@ -399,16 +398,15 @@
 }
 
 // Test that exactly one extension is loaded, and return it.
-const extensions::Extension* ExtensionApiTest::GetSingleLoadedExtension() {
-  extensions::ExtensionRegistry* registry =
-      extensions::ExtensionRegistry::Get(browser()->profile());
+const Extension* ExtensionApiTest::GetSingleLoadedExtension() {
+  ExtensionRegistry* registry = ExtensionRegistry::Get(browser()->profile());
 
-  const extensions::Extension* result = NULL;
-  for (const scoped_refptr<const extensions::Extension>& extension :
+  const Extension* result = NULL;
+  for (const scoped_refptr<const Extension>& extension :
        registry->enabled_extensions()) {
     // Ignore any component extensions. They are automatically loaded into all
     // profiles and aren't the extension we're looking for here.
-    if (extension->location() == extensions::Manifest::COMPONENT)
+    if (extension->location() == Manifest::COMPONENT)
       continue;
 
     if (result != NULL) {
@@ -496,12 +494,14 @@
 
   test_data_dir_ = test_data_dir_.AppendASCII("api_test");
 
-  extensions::RegisterPathProvider();
-  base::PathService::Get(extensions::DIR_TEST_DATA, &shared_test_data_dir_);
+  RegisterPathProvider();
+  base::PathService::Get(DIR_TEST_DATA, &shared_test_data_dir_);
   shared_test_data_dir_ = shared_test_data_dir_.AppendASCII("api_test");
 
   // Backgrounded renderer processes run at a lower priority, causing the
   // tests to take more time to complete. Disable backgrounding so that the
   // tests don't time out.
-  command_line->AppendSwitch(switches::kDisableRendererBackgrounding);
+  command_line->AppendSwitch(::switches::kDisableRendererBackgrounding);
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_apitest.h b/chrome/browser/extensions/extension_apitest.h
index e3f7ebb..34265a3 100644
--- a/chrome/browser/extensions/extension_apitest.h
+++ b/chrome/browser/extensions/extension_apitest.h
@@ -19,7 +19,6 @@
 
 namespace extensions {
 class Extension;
-}
 
 // The general flow of these API tests should work like this:
 // (1) Setup initial browser state (e.g. create some bookmarks for the
@@ -29,7 +28,7 @@
 //     chrome.test.fail
 // (4) Verify expected browser state.
 // TODO(erikkay): There should also be a way to drive events in these tests.
-class ExtensionApiTest : public extensions::ExtensionBrowserTest {
+class ExtensionApiTest : public ExtensionBrowserTest {
  public:
   // Flags used to configure how the tests are run.
   // TODO(aa): Many of these are dupes of ExtensionBrowserTest::Flags. Combine
@@ -207,7 +206,7 @@
 
   // Test that exactly one extension loaded.  If so, return a pointer to
   // the extension.  If not, return NULL and set message_.
-  const extensions::Extension* GetSingleLoadedExtension();
+  const Extension* GetSingleLoadedExtension();
 
   // All extensions tested by ExtensionApiTest are in the "api_test" dir.
   void SetUpCommandLine(base::CommandLine* command_line) override;
@@ -239,4 +238,6 @@
   base::FilePath shared_test_data_dir_;
 };
 
+}  // namespace extensions
+
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_APITEST_H_
diff --git a/chrome/browser/extensions/extension_dom_clipboard_apitest.cc b/chrome/browser/extensions/extension_dom_clipboard_apitest.cc
index 09587df..7af0348b 100644
--- a/chrome/browser/extensions/extension_dom_clipboard_apitest.cc
+++ b/chrome/browser/extensions/extension_dom_clipboard_apitest.cc
@@ -17,10 +17,10 @@
 
 namespace {
 
-class ClipboardApiTest : public ExtensionApiTest {
+class ClipboardApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
   }
 
diff --git a/chrome/browser/extensions/extension_fileapi_apitest.cc b/chrome/browser/extensions/extension_fileapi_apitest.cc
index e920a935..41adc37d 100644
--- a/chrome/browser/extensions/extension_fileapi_apitest.cc
+++ b/chrome/browser/extensions/extension_fileapi_apitest.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, DISABLED_FileAPI) {
   ASSERT_TRUE(RunExtensionTest("fileapi")) << message_;
 }
@@ -16,3 +18,5 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, RequestQuotaInBackgroundPage) {
   ASSERT_TRUE(RunExtensionTest("request_quota_background")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_fullscreen_apitest.cc b/chrome/browser/extensions/extension_fullscreen_apitest.cc
index 6cf1c60..1a45ed0 100644
--- a/chrome/browser/extensions/extension_fullscreen_apitest.cc
+++ b/chrome/browser/extensions/extension_fullscreen_apitest.cc
@@ -8,6 +8,8 @@
 #include "chrome/browser/ui/exclusive_access/exclusive_access_context.h"
 #include "chrome/browser/ui/exclusive_access/exclusive_access_manager.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest,
                        ExtensionFullscreenAccessFail) {
   // Test that fullscreen cannot be accessed from an extension without
@@ -69,3 +71,5 @@
                        MAYBE_DisplayModeWindowIsInFullscreen) {
   ASSERT_TRUE(RunPlatformAppTest("fullscreen/mq_display_mode")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_geolocation_apitest.cc b/chrome/browser/extensions/extension_geolocation_apitest.cc
index eda7310..8d35684 100644
--- a/chrome/browser/extensions/extension_geolocation_apitest.cc
+++ b/chrome/browser/extensions/extension_geolocation_apitest.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "device/geolocation/public/cpp/scoped_geolocation_overrider.h"
 
-class GeolocationApiTest : public ExtensionApiTest {
+class GeolocationApiTest : public extensions::ExtensionApiTest {
  public:
   GeolocationApiTest() {
   }
diff --git a/chrome/browser/extensions/extension_get_views_apitest.cc b/chrome/browser/extensions/extension_get_views_apitest.cc
index 1559a65..73e0943 100644
--- a/chrome/browser/extensions/extension_get_views_apitest.cc
+++ b/chrome/browser/extensions/extension_get_views_apitest.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, GetViews) {
   ASSERT_TRUE(RunExtensionTest("get_views")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_icon_source_apitest.cc b/chrome/browser/extensions/extension_icon_source_apitest.cc
index 09068e894..68ac94e 100644
--- a/chrome/browser/extensions/extension_icon_source_apitest.cc
+++ b/chrome/browser/extensions/extension_icon_source_apitest.cc
@@ -16,7 +16,7 @@
 #include "net/dns/mock_host_resolver.h"
 #include "url/gurl.h"
 
-using ExtensionIconSourceTest = ExtensionApiTest;
+using ExtensionIconSourceTest = extensions::ExtensionApiTest;
 
 // Times out on Mac and Win. http://crbug.com/238705
 #if defined(OS_WIN) || defined(OS_MACOSX)
diff --git a/chrome/browser/extensions/extension_incognito_apitest.cc b/chrome/browser/extensions/extension_incognito_apitest.cc
index 3a37473..7d432e6 100644
--- a/chrome/browser/extensions/extension_incognito_apitest.cc
+++ b/chrome/browser/extensions/extension_incognito_apitest.cc
@@ -22,10 +22,10 @@
 using content::WebContents;
 using extensions::ResultCatcher;
 
-class IncognitoApiTest : public ExtensionApiTest {
+class IncognitoApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
diff --git a/chrome/browser/extensions/extension_javascript_url_apitest.cc b/chrome/browser/extensions/extension_javascript_url_apitest.cc
index bac248f..2291b1d 100644
--- a/chrome/browser/extensions/extension_javascript_url_apitest.cc
+++ b/chrome/browser/extensions/extension_javascript_url_apitest.cc
@@ -5,10 +5,10 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "net/dns/mock_host_resolver.h"
 
-class JavscriptApiTest : public ExtensionApiTest {
+class JavscriptApiTest : public extensions::ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
diff --git a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
index 8249cffa..0d36b28 100644
--- a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
+++ b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
@@ -19,10 +19,10 @@
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "url/gurl.h"
 
-class ExtensionResourceRequestPolicyTest : public ExtensionApiTest {
+class ExtensionResourceRequestPolicyTest : public extensions::ExtensionApiTest {
  protected:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(embedded_test_server()->Start());
   }
diff --git a/chrome/browser/extensions/extension_storage_apitest.cc b/chrome/browser/extensions/extension_storage_apitest.cc
index 299091c..ff8623a 100644
--- a/chrome/browser/extensions/extension_storage_apitest.cc
+++ b/chrome/browser/extensions/extension_storage_apitest.cc
@@ -5,6 +5,8 @@
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 #if defined(OS_WIN)
 // Always fails on Windows after r110181: http://crbug.com/104419.
 #define MAYBE_Storage DISABLED_Storage
@@ -14,3 +16,5 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MAYBE_Storage) {
   ASSERT_TRUE(RunExtensionTest("storage")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_tabs_apitest.cc b/chrome/browser/extensions/extension_tabs_apitest.cc
index 36c8b46..c1bf367 100644
--- a/chrome/browser/extensions/extension_tabs_apitest.cc
+++ b/chrome/browser/extensions/extension_tabs_apitest.cc
@@ -20,10 +20,10 @@
 #include "ui/aura/window_tree_host.h"
 #endif
 
-class ExtensionApiTabTest : public ExtensionApiTest {
+class ExtensionApiTabTest : public extensions::ExtensionApiTest {
  public:
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(StartEmbeddedTestServer());
   }
diff --git a/chrome/browser/extensions/extension_websocket_apitest.cc b/chrome/browser/extensions/extension_websocket_apitest.cc
index e26d5e4..4501c425 100644
--- a/chrome/browser/extensions/extension_websocket_apitest.cc
+++ b/chrome/browser/extensions/extension_websocket_apitest.cc
@@ -7,7 +7,11 @@
 #include "net/dns/mock_host_resolver.h"
 #include "net/test/test_data_directory.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, WebSocket) {
   ASSERT_TRUE(StartWebSocketServer(net::GetWebSocketTestDataDirectory()));
   ASSERT_TRUE(RunExtensionTest("websocket")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/extension_with_management_policy_apitest.cc b/chrome/browser/extensions/extension_with_management_policy_apitest.cc
index 3b77f73d..176325c 100644
--- a/chrome/browser/extensions/extension_with_management_policy_apitest.cc
+++ b/chrome/browser/extensions/extension_with_management_policy_apitest.cc
@@ -7,13 +7,11 @@
 #include "net/dns/mock_host_resolver.h"
 #include "net/test/embedded_test_server/http_request.h"
 
-ExtensionApiTestWithManagementPolicy::ExtensionApiTestWithManagementPolicy()
-    : ExtensionApiTest() {}
-
+ExtensionApiTestWithManagementPolicy::ExtensionApiTestWithManagementPolicy() {}
 ExtensionApiTestWithManagementPolicy::~ExtensionApiTestWithManagementPolicy() {}
 
 void ExtensionApiTestWithManagementPolicy::SetUpInProcessBrowserTestFixture() {
-  ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+  extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
   embedded_test_server()->RegisterRequestMonitor(
       base::Bind(&ExtensionApiTestWithManagementPolicy::MonitorRequestHandler,
                  base::Unretained(this)));
@@ -25,7 +23,7 @@
 }
 
 void ExtensionApiTestWithManagementPolicy::SetUpOnMainThread() {
-  ExtensionApiTest::SetUpOnMainThread();
+  extensions::ExtensionApiTest::SetUpOnMainThread();
   host_resolver()->AddRule("*", "127.0.0.1");
 }
 
diff --git a/chrome/browser/extensions/extension_with_management_policy_apitest.h b/chrome/browser/extensions/extension_with_management_policy_apitest.h
index e57aff4..1e8223d0 100644
--- a/chrome/browser/extensions/extension_with_management_policy_apitest.h
+++ b/chrome/browser/extensions/extension_with_management_policy_apitest.h
@@ -20,7 +20,8 @@
 // The ExtensionSettings policy affects host permissions which impacts several
 // API integration tests. This class enables easy declaration of
 // ExtensionSettings policies and functions commonly used during these tests.
-class ExtensionApiTestWithManagementPolicy : public ExtensionApiTest {
+class ExtensionApiTestWithManagementPolicy
+    : public extensions::ExtensionApiTest {
  public:
   ExtensionApiTestWithManagementPolicy();
   ~ExtensionApiTestWithManagementPolicy() override;
diff --git a/chrome/browser/extensions/mutation_observers_apitest.cc b/chrome/browser/extensions/mutation_observers_apitest.cc
index 713937bf..67b92bf 100644
--- a/chrome/browser/extensions/mutation_observers_apitest.cc
+++ b/chrome/browser/extensions/mutation_observers_apitest.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MutationObservers) {
   ASSERT_TRUE(RunExtensionTest("mutation_observers")) << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/sandboxed_pages_apitest.cc b/chrome/browser/extensions/sandboxed_pages_apitest.cc
index 4245106..578952d6 100644
--- a/chrome/browser/extensions/sandboxed_pages_apitest.cc
+++ b/chrome/browser/extensions/sandboxed_pages_apitest.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, SandboxedPages) {
   EXPECT_TRUE(RunExtensionSubtest("sandboxed_pages", "main.html")) << message_;
 }
@@ -18,3 +20,5 @@
                                   kFlagIgnoreManifestWarnings))
       << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/shared_module_apitest.cc b/chrome/browser/extensions/shared_module_apitest.cc
index 9292c98c..edf70b4 100644
--- a/chrome/browser/extensions/shared_module_apitest.cc
+++ b/chrome/browser/extensions/shared_module_apitest.cc
@@ -5,7 +5,7 @@
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "extensions/test/extension_test_message_listener.h"
 
-using extensions::Extension;
+namespace extensions {
 
 // NB: We use LoadExtension instead of InstallExtension for shared modules so
 // the public-keys in their manifests are used to generate the extension ID, so
@@ -55,3 +55,5 @@
 
   EXPECT_TRUE(RunExtensionTest("shared_module/import_locales"));
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/stubs_apitest.cc b/chrome/browser/extensions/stubs_apitest.cc
index fc819407..ec28c8fd 100644
--- a/chrome/browser/extensions/stubs_apitest.cc
+++ b/chrome/browser/extensions/stubs_apitest.cc
@@ -10,6 +10,8 @@
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "url/gurl.h"
 
+namespace extensions {
+
 // Tests that we throw errors when you try using extension APIs that aren't
 // supported in content scripts.
 // Timey-outy on mac. http://crbug.com/89116
@@ -28,7 +30,7 @@
   GURL url(embedded_test_server()->GetURL("/extensions/test_file.html"));
   ui_test_utils::NavigateToURL(browser(), url);
 
-  extensions::ResultCatcher catcher;
+  ResultCatcher catcher;
   ASSERT_TRUE(catcher.GetNextResult());
 }
 
@@ -40,3 +42,5 @@
       "stubs_app", static_cast<int>(kFlagIgnoreManifestWarnings)))
       << message_;
 }
+
+}  // namespace extensions
diff --git a/chrome/browser/extensions/window_open_interactive_apitest.cc b/chrome/browser/extensions/window_open_interactive_apitest.cc
index 4a2c3f6e..92daf3d 100644
--- a/chrome/browser/extensions/window_open_interactive_apitest.cc
+++ b/chrome/browser/extensions/window_open_interactive_apitest.cc
@@ -6,6 +6,8 @@
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 
+namespace extensions {
+
 // http://crbug.com/253417 for NDEBUG
 #if (defined(OS_WIN) || defined(OS_MACOSX)) && defined(NDEBUG)
 // Focus test fails if there is no window manager on Linux.
@@ -13,3 +15,5 @@
   ASSERT_TRUE(RunExtensionTest("window_open/focus")) << message_;
 }
 #endif
+
+}  // namespace extensions
diff --git a/chrome/browser/pdf/pdf_extension_test.cc b/chrome/browser/pdf/pdf_extension_test.cc
index 842dc8b0..f41edfe 100644
--- a/chrome/browser/pdf/pdf_extension_test.cc
+++ b/chrome/browser/pdf/pdf_extension_test.cc
@@ -105,7 +105,7 @@
   return false;
 }
 
-class PDFExtensionTest : public ExtensionApiTest {
+class PDFExtensionTest : public extensions::ExtensionApiTest {
  public:
   ~PDFExtensionTest() override {}
 
@@ -114,7 +114,7 @@
   }
 
   void SetUpOnMainThread() override {
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
     host_resolver()->AddRule("*", "127.0.0.1");
     ASSERT_TRUE(embedded_test_server()->InitializeAndListen());
     content::SetupCrossSiteRedirector(embedded_test_server());
@@ -123,7 +123,7 @@
 
   void TearDownOnMainThread() override {
     ASSERT_TRUE(embedded_test_server()->ShutdownAndWaitUntilComplete());
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   bool PdfIsExpectedToLoad(const std::string& pdf_file) {
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index db8a5d9..32b922cb 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -2629,7 +2629,7 @@
 
 // Test interaction of the webNavigation and tabs API with prerender.
 class PrerenderBrowserTestWithExtensions : public PrerenderBrowserTest,
-                                           public ExtensionApiTest {
+                                           public extensions::ExtensionApiTest {
  public:
   PrerenderBrowserTestWithExtensions() {
     // The individual tests start the test server through ExtensionApiTest, so
@@ -2640,27 +2640,27 @@
   void SetUp() override { PrerenderBrowserTest::SetUp(); }
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
+    extensions::ExtensionApiTest::SetUpCommandLine(command_line);
   }
 
   void SetUpInProcessBrowserTestFixture() override {
     PrerenderBrowserTest::SetUpInProcessBrowserTestFixture();
-    ExtensionApiTest::SetUpInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::SetUpInProcessBrowserTestFixture();
   }
 
   void TearDownInProcessBrowserTestFixture() override {
     PrerenderBrowserTest::TearDownInProcessBrowserTestFixture();
-    ExtensionApiTest::TearDownInProcessBrowserTestFixture();
+    extensions::ExtensionApiTest::TearDownInProcessBrowserTestFixture();
   }
 
   void TearDownOnMainThread() override {
     PrerenderBrowserTest::TearDownOnMainThread();
-    ExtensionApiTest::TearDownOnMainThread();
+    extensions::ExtensionApiTest::TearDownOnMainThread();
   }
 
   void SetUpOnMainThread() override {
     PrerenderBrowserTest::SetUpOnMainThread();
-    ExtensionApiTest::SetUpOnMainThread();
+    extensions::ExtensionApiTest::SetUpOnMainThread();
   }
 };
 
diff --git a/chrome/browser/safe_browsing/settings_reset_prompt/settings_reset_prompt_model_browsertest_win.cc b/chrome/browser/safe_browsing/settings_reset_prompt/settings_reset_prompt_model_browsertest_win.cc
index 21f860e..62b2fa7c 100644
--- a/chrome/browser/safe_browsing/settings_reset_prompt/settings_reset_prompt_model_browsertest_win.cc
+++ b/chrome/browser/safe_browsing/settings_reset_prompt/settings_reset_prompt_model_browsertest_win.cc
@@ -97,7 +97,8 @@
     "  }"
     "}";
 
-class SettingsResetPromptModelBrowserTest : public extensions::ExtensionBrowserTest {
+class SettingsResetPromptModelBrowserTest
+    : public extensions::ExtensionBrowserTest {
  public:
   virtual void OnResetDone() { ++reset_callbacks_; }
 
diff --git a/chrome/browser/ui/views/extensions/bookmark_override_browsertest.cc b/chrome/browser/ui/views/extensions/bookmark_override_browsertest.cc
index f4221a9..6cdf841 100644
--- a/chrome/browser/ui/views/extensions/bookmark_override_browsertest.cc
+++ b/chrome/browser/ui/views/extensions/bookmark_override_browsertest.cc
@@ -19,7 +19,7 @@
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "ui/events/event_utils.h"
 
-typedef ExtensionApiTest BookmarkOverrideTest;
+typedef extensions::ExtensionApiTest BookmarkOverrideTest;
 
 namespace {
 // Bookmark this page keybinding.