diff --git a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
index 8c7a131d..31e0aa8 100644
--- a/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
+++ b/chrome/browser/extensions/api/cast_streaming/cast_streaming_apitest.cc
@@ -386,7 +386,7 @@
   receiver->Stop();
 
   delete receiver;
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   cast_environment->Shutdown();
 }
 
diff --git a/chrome/browser/extensions/api/commands/command_service_browsertest.cc b/chrome/browser/extensions/api/commands/command_service_browsertest.cc
index cfd932f..efdef90 100644
--- a/chrome/browser/extensions/api/commands/command_service_browsertest.cc
+++ b/chrome/browser/extensions/api/commands/command_service_browsertest.cc
@@ -46,7 +46,7 @@
 typedef ExtensionApiTest CommandServiceTest;
 
 IN_PROC_BROWSER_TEST_F(CommandServiceTest, RemoveShortcutSurvivesUpdate) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
diff --git a/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc b/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
index b4d3fb3..d133a69 100644
--- a/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
+++ b/chrome/browser/extensions/api/downloads/downloads_api_browsertest.cc
@@ -694,7 +694,7 @@
                                    const storage::FileSystemURL& path,
                                    const char* data,
                                    int length) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     // Create a temp file.
     base::FilePath temp_file;
     if (!base::CreateTemporaryFile(&temp_file) ||
@@ -1051,7 +1051,7 @@
   base::FilePath fake_path = all_downloads[1]->GetTargetFilePath();
 
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     EXPECT_EQ(0, base::WriteFile(real_path, "", 0));
     ASSERT_TRUE(base::PathExists(real_path));
     ASSERT_FALSE(base::PathExists(fake_path));
@@ -2585,7 +2585,7 @@
                           "    \"previous\": \"in_progress\","
                           "    \"current\": \"complete\"}}]",
                           result_id)));
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   std::string disk_data;
   EXPECT_TRUE(base::ReadFileToString(item->GetTargetFilePath(), &disk_data));
   EXPECT_STREQ(kPayloadData, disk_data.c_str());
diff --git a/chrome/browser/extensions/api/extension_action/browser_action_apitest.cc b/chrome/browser/extensions/api/extension_action/browser_action_apitest.cc
index 30400437..9d3ecde 100644
--- a/chrome/browser/extensions/api/extension_action/browser_action_apitest.cc
+++ b/chrome/browser/extensions/api/extension_action/browser_action_apitest.cc
@@ -73,7 +73,7 @@
 
 std::unique_ptr<base::ScopedTempDir> CreateAndSetDownloadsDirectory(
     PrefService* pref_service) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   std::unique_ptr<base::ScopedTempDir> dir(new base::ScopedTempDir);
 
   if (!dir->CreateUniqueTempDir())
@@ -999,7 +999,7 @@
   // Override the default downloads directory, so that the test can cleanup
   // after itself.  This section is based on CreateAndSetDownloadsDirectory
   // method defined in a few other source files with tests.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   std::unique_ptr<base::ScopedTempDir> downloads_directory =
       CreateAndSetDownloadsDirectory(browser()->profile()->GetPrefs());
   ASSERT_TRUE(downloads_directory);
diff --git a/chrome/browser/extensions/api/file_system/file_system_apitest.cc b/chrome/browser/extensions/api/file_system/file_system_apitest.cc
index fde936c0..50a2b82 100644
--- a/chrome/browser/extensions/api/file_system/file_system_apitest.cc
+++ b/chrome/browser/extensions/api/file_system/file_system_apitest.cc
@@ -89,7 +89,7 @@
  protected:
   base::FilePath TempFilePath(const std::string& destination_name,
                               bool copy_gold) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     if (!temp_dir_.CreateUniqueTempDir()) {
       ADD_FAILURE() << "CreateUniqueTempDir failed";
       return base::FilePath();
@@ -109,7 +109,7 @@
   std::vector<base::FilePath> TempFilePaths(
       const std::vector<std::string>& destination_names,
       bool copy_gold) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     if (!temp_dir_.CreateUniqueTempDir()) {
       ADD_FAILURE() << "CreateUniqueTempDir failed";
       return std::vector<base::FilePath>();
@@ -132,7 +132,7 @@
   }
 
   void CheckStoredDirectoryMatches(const base::FilePath& filename) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     const Extension* extension = GetSingleLoadedExtension();
     ASSERT_TRUE(extension);
     std::string extension_id = extension->id();
@@ -162,7 +162,7 @@
 #if defined(OS_WIN) || defined(OS_POSIX)
 IN_PROC_BROWSER_TEST_F(FileSystemApiTest, FileSystemApiGetDisplayPathPrettify) {
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         base::DIR_HOME, test_root_folder_, false, false));
   }
@@ -180,7 +180,7 @@
     FileSystemApiGetDisplayPathPrettifyMac) {
   base::FilePath test_file;
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     // On Mac, "test.localized" will be localized into just "test".
     base::FilePath test_path = TempFilePath("test.localized", false);
     ASSERT_TRUE(base::CreateDirectory(test_path));
@@ -229,7 +229,7 @@
   base::FilePath test_file = TempFilePath("open_existing.txt", true);
   ASSERT_FALSE(test_file.empty());
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         chrome::DIR_USER_DOCUMENTS, test_file.DirName(), false, false));
   }
@@ -253,7 +253,7 @@
   base::FilePath test_file = TempFilePath("open_existing.txt", true);
   ASSERT_FALSE(test_file.empty());
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         chrome::DIR_USER_DOCUMENTS, test_file.DirName(), false, false));
   }
@@ -268,7 +268,7 @@
   base::FilePath test_file = TempFilePath("open_existing.txt", true);
   ASSERT_FALSE(test_file.empty());
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         chrome::DIR_USER_DOCUMENTS, test_file.DirName(), false, false));
   }
@@ -350,7 +350,7 @@
   ASSERT_FALSE(test_file.empty());
   base::FilePath test_directory = test_file.DirName();
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         kGraylistedPath, test_directory, false, false));
   }
@@ -368,7 +368,7 @@
   ASSERT_FALSE(test_file.empty());
   base::FilePath test_directory = test_file.DirName();
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         kGraylistedPath, test_directory, false, false));
   }
@@ -387,7 +387,7 @@
   base::FilePath test_directory = test_file.DirName();
   base::FilePath parent_directory = test_directory.DirName();
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         kGraylistedPath, test_directory, false, false));
   }
@@ -409,7 +409,7 @@
   base::FilePath test_directory = test_file.DirName();
   base::FilePath parent_directory = test_directory.DirName();
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::OverrideAndCreateIfNeeded(
         kGraylistedPath, parent_directory, false, false));
   }
diff --git a/chrome/browser/extensions/api/i18n/i18n_apitest.cc b/chrome/browser/extensions/api/i18n/i18n_apitest.cc
index 0a1735a..6eda361 100644
--- a/chrome/browser/extensions/api/i18n/i18n_apitest.cc
+++ b/chrome/browser/extensions/api/i18n/i18n_apitest.cc
@@ -22,7 +22,7 @@
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, I18NUpdate) {
   ASSERT_TRUE(embedded_test_server()->Start());
   // Create an Extension whose messages.json file will be updated.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir extension_dir;
   ASSERT_TRUE(extension_dir.CreateUniqueTempDir());
   base::CopyFile(
diff --git a/chrome/browser/extensions/api/image_writer_private/image_writer_utility_client_browsertest.cc b/chrome/browser/extensions/api/image_writer_private/image_writer_utility_client_browsertest.cc
index dc42c2d..4df504c 100644
--- a/chrome/browser/extensions/api/image_writer_private/image_writer_utility_client_browsertest.cc
+++ b/chrome/browser/extensions/api/image_writer_private/image_writer_utility_client_browsertest.cc
@@ -29,14 +29,14 @@
 class ImageWriterUtilityClientTest : public InProcessBrowserTest {
  public:
   ImageWriterUtilityClientTest() {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     test_device_ = base::FilePath().AppendASCII(
         extensions::mojom::RemovableStorageWriter::kTestDevice);
     EXPECT_TRUE(temp_dir_.CreateUniqueTempDir());
   }
 
   void FillImageFileWithPattern(char pattern) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     EXPECT_TRUE(base::CreateTemporaryFileInDir(temp_dir_.GetPath(), &image_));
 
     base::RunLoop run_loop;
diff --git a/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc b/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
index a810a65..b2e8d86 100644
--- a/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
+++ b/chrome/browser/extensions/api/media_galleries/media_galleries_apitest.cc
@@ -107,7 +107,7 @@
         test_data_dir_.AppendASCII(kTestDir + extension_name);
     from_dir = from_dir.NormalizePathSeparators();
 
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     base::ScopedTempDir temp_dir;
     if (!temp_dir.CreateUniqueTempDir())
       return false;
@@ -168,7 +168,7 @@
   // with no default media galleries, such as CHROMEOS. This fake gallery is
   // pre-populated with a test.jpg and test.txt.
   void MakeSingleFakeGallery(MediaGalleryPrefId* pref_id) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_FALSE(fake_gallery_temp_dir_.IsValid());
     ASSERT_TRUE(fake_gallery_temp_dir_.CreateUniqueTempDir());
 
@@ -200,7 +200,7 @@
   }
 
   void AddFileToSingleFakeGallery(const base::FilePath& source_path) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(fake_gallery_temp_dir_.IsValid());
 
     ASSERT_TRUE(base::CopyFile(
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 e8e43de0..0e662e5 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
@@ -110,7 +110,7 @@
   }
 
   bool AddNewFileInTestGallery() {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     base::FilePath gallery_file =
         test_gallery_.GetPath().Append(FILE_PATH_LITERAL("test1.txt"));
     std::string content("new content");
diff --git a/chrome/browser/extensions/api/messaging/native_messaging_test_util.cc b/chrome/browser/extensions/api/messaging/native_messaging_test_util.cc
index 3c28d3e..4067196 100644
--- a/chrome/browser/extensions/api/messaging/native_messaging_test_util.cc
+++ b/chrome/browser/extensions/api/messaging/native_messaging_test_util.cc
@@ -69,7 +69,7 @@
 ScopedTestNativeMessagingHost::ScopedTestNativeMessagingHost() {}
 
 void ScopedTestNativeMessagingHost::RegisterTestHost(bool user_level) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
   ScopedTestNativeMessagingHost test_host;
 
@@ -102,7 +102,7 @@
 }
 
 ScopedTestNativeMessagingHost::~ScopedTestNativeMessagingHost() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ignore_result(temp_dir_.Delete());
 }
 
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 6bc8dc15..df5f8b07 100644
--- a/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc
+++ b/chrome/browser/extensions/api/page_capture/page_capture_apitest.cc
@@ -62,7 +62,7 @@
   content::RunAllPendingInMessageLoop(content::BrowserThread::IO);
   // Make sure the temporary file is destroyed once the javascript side reads
   // the contents.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ASSERT_FALSE(base::PathExists(delegate.temp_file_));
 }
 
@@ -78,7 +78,7 @@
   ASSERT_FALSE(delegate.temp_file_.empty());
   content::RunAllTasksUntilIdle();
   content::RunAllPendingInMessageLoop(content::BrowserThread::IO);
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ASSERT_FALSE(base::PathExists(delegate.temp_file_));
 }
 
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 2238cca..23278aec 100644
--- a/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc
+++ b/chrome/browser/extensions/api/streams_private/streams_private_apitest.cc
@@ -152,7 +152,7 @@
   }
 
   void InitializeDownloadSettings() {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(browser());
     ASSERT_TRUE(downloads_dir_.CreateUniqueTempDir());
 
diff --git a/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc b/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
index 16c58cb3..da1fc21 100644
--- a/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
+++ b/chrome/browser/extensions/api/web_navigation/web_navigation_apitest.cc
@@ -404,7 +404,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(WebNavigationApiTest, Download) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir download_directory;
   ASSERT_TRUE(download_directory.CreateUniqueTempDir());
   DownloadPrefs* download_prefs =
diff --git a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_event_log_apitest.cc b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_event_log_apitest.cc
index e13d805..4a8f8d6 100644
--- a/chrome/browser/extensions/api/webrtc_logging_private/webrtc_event_log_apitest.cc
+++ b/chrome/browser/extensions/api/webrtc_logging_private/webrtc_event_log_apitest.cc
@@ -67,7 +67,7 @@
       : found_(false), path_(path) {}
 
   bool Start() {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     if (base::PathExists(path_)) {
       found_ = true;
       return true;
@@ -236,7 +236,7 @@
   ASSERT_TRUE(waiter->Start()) << "ERROR watching for "
                                << full_file_name.value();
   ASSERT_TRUE(waiter->WaitForFile());
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ASSERT_TRUE(base::PathExists(full_file_name));
   EXPECT_TRUE(base::GetFileSize(full_file_name, &file_size));
   EXPECT_GT(file_size, 0);
@@ -247,7 +247,7 @@
 
 IN_PROC_BROWSER_TEST_F(WebrtcEventLogApiTest,
                        TestStartTimedWebRtcEventLogging) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ASSERT_TRUE(embedded_test_server()->Start());
 
   content::WebContents* left_tab =
diff --git a/chrome/browser/extensions/api/webstore_private/webstore_private_apitest.cc b/chrome/browser/extensions/api/webstore_private/webstore_private_apitest.cc
index 6c441e1..ef75b258 100644
--- a/chrome/browser/extensions/api/webstore_private/webstore_private_apitest.cc
+++ b/chrome/browser/extensions/api/webstore_private/webstore_private_apitest.cc
@@ -221,7 +221,7 @@
 // Test having the default download directory missing.
 IN_PROC_BROWSER_TEST_F(ExtensionWebstorePrivateApiTest, MissingDownloadDir) {
   // Set a non-existent directory as the download path.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir temp_dir;
   EXPECT_TRUE(temp_dir.CreateUniqueTempDir());
   base::FilePath missing_directory = temp_dir.Take();
diff --git a/chrome/browser/extensions/app_background_page_apitest.cc b/chrome/browser/extensions/app_background_page_apitest.cc
index fa7e17d..5e2d85da 100644
--- a/chrome/browser/extensions/app_background_page_apitest.cc
+++ b/chrome/browser/extensions/app_background_page_apitest.cc
@@ -65,7 +65,7 @@
 
   bool CreateApp(const std::string& app_manifest,
                  base::FilePath* app_dir) {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     if (!app_dir_.CreateUniqueTempDir()) {
       LOG(ERROR) << "Unable to create a temporary directory.";
       return false;
@@ -141,7 +141,7 @@
 
  protected:
   void LaunchTestingApp() {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     base::FilePath app_dir;
     PathService::Get(chrome::DIR_GEN_TEST_DATA, &app_dir);
     app_dir = app_dir.AppendASCII(
diff --git a/chrome/browser/extensions/app_process_apitest.cc b/chrome/browser/extensions/app_process_apitest.cc
index a650aec..4da3174 100644
--- a/chrome/browser/extensions/app_process_apitest.cc
+++ b/chrome/browser/extensions/app_process_apitest.cc
@@ -324,7 +324,7 @@
   std::string error;
   scoped_refptr<const Extension> extension;
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     extension = extensions::file_util::LoadExtension(
         test_data_dir_.AppendASCII("app_process"),
         extensions::Manifest::UNPACKED, Extension::FROM_BOOKMARK, &error);
diff --git a/chrome/browser/extensions/chrome_test_extension_loader.cc b/chrome/browser/extensions/chrome_test_extension_loader.cc
index 600586a..3b113bb 100644
--- a/chrome/browser/extensions/chrome_test_extension_loader.cc
+++ b/chrome/browser/extensions/chrome_test_extension_loader.cc
@@ -38,7 +38,7 @@
 ChromeTestExtensionLoader::~ChromeTestExtensionLoader() {
   // If there was a temporary directory created for a CRX, we need to clean it
   // up before the member is destroyed so we can explicitly allow IO.
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   if (temp_dir_.IsValid())
     EXPECT_TRUE(temp_dir_.Delete());
 }
@@ -109,7 +109,7 @@
 
 base::FilePath ChromeTestExtensionLoader::PackExtension(
     const base::FilePath& unpacked_path) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   if (!base::PathExists(unpacked_path)) {
     ADD_FAILURE() << "Unpacked path does not exist: " << unpacked_path.value();
     return base::FilePath();
diff --git a/chrome/browser/extensions/content_verifier_browsertest.cc b/chrome/browser/extensions/content_verifier_browsertest.cc
index b4997ef..c0e76a2 100644
--- a/chrome/browser/extensions/content_verifier_browsertest.cc
+++ b/chrome/browser/extensions/content_verifier_browsertest.cc
@@ -542,7 +542,7 @@
     base::FilePath scriptfile = extension->path().AppendASCII(script_relpath);
     std::string extra = "some_extra_function_call();";
     {
-      base::ThreadRestrictions::ScopedAllowIO allow_io;
+      base::ScopedAllowBlockingForTesting allow_blocking;
       ASSERT_TRUE(base::AppendToFile(scriptfile, extra.data(), extra.size()));
     }
     DisableExtension(id);
diff --git a/chrome/browser/extensions/extension_browsertest.cc b/chrome/browser/extensions/extension_browsertest.cc
index 1c79dfb..009bf95 100644
--- a/chrome/browser/extensions/extension_browsertest.cc
+++ b/chrome/browser/extensions/extension_browsertest.cc
@@ -157,7 +157,7 @@
 const Extension* ExtensionBrowserTest::GetExtensionByPath(
     const extensions::ExtensionSet& extensions,
     const base::FilePath& path) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::FilePath extension_path = base::MakeAbsoluteFilePath(path);
   EXPECT_TRUE(!extension_path.empty());
   for (const scoped_refptr<const Extension>& extension : extensions) {
@@ -264,7 +264,7 @@
       profile())->extension_service();
   ExtensionRegistry* registry = ExtensionRegistry::Get(profile());
 
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   std::string manifest;
   if (!base::ReadFileToString(path.Append(manifest_relative_path), &manifest)) {
     return NULL;
@@ -321,7 +321,7 @@
 
 base::FilePath ExtensionBrowserTest::PackExtension(
     const base::FilePath& dir_path) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::FilePath crx_path = temp_dir_.GetPath().AppendASCII("temp.crx");
   if (!base::DeleteFile(crx_path, false)) {
     ADD_FAILURE() << "Failed to delete crx: " << crx_path.value();
@@ -350,7 +350,7 @@
     const base::FilePath& crx_path,
     const base::FilePath& pem_path,
     const base::FilePath& pem_out_path) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   if (!base::PathExists(dir_path)) {
     ADD_FAILURE() << "Extension dir not found: " << dir_path.value();
     return base::FilePath();
diff --git a/chrome/browser/extensions/extension_keybinding_apitest.cc b/chrome/browser/extensions/extension_keybinding_apitest.cc
index b477aad..4b319f81 100644
--- a/chrome/browser/extensions/extension_keybinding_apitest.cc
+++ b/chrome/browser/extensions/extension_keybinding_apitest.cc
@@ -559,7 +559,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest, ShortcutAddedOnUpdate) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -605,7 +605,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest, ShortcutChangedOnUpdate) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -654,7 +654,7 @@
 }
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest, ShortcutRemovedOnUpdate) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -701,7 +701,7 @@
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest,
                        ShortcutAddedOnUpdateAfterBeingAssignedByUser) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -752,7 +752,7 @@
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest,
                        ShortcutChangedOnUpdateAfterBeingReassignedByUser) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -807,7 +807,7 @@
 // Test that Media keys do not overwrite previous settings.
 IN_PROC_BROWSER_TEST_F(CommandsApiTest,
     MediaKeyShortcutChangedOnUpdateAfterBeingReassignedByUser) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
@@ -861,7 +861,7 @@
 
 IN_PROC_BROWSER_TEST_F(CommandsApiTest,
                        ShortcutRemovedOnUpdateAfterBeingReassignedByUser) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   EXPECT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.
diff --git a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
index 627246cb..b9f5609 100644
--- a/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
+++ b/chrome/browser/extensions/extension_resource_request_policy_apitest.cc
@@ -83,7 +83,7 @@
   // resources.
   std::string file_source;
   {
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(base::ReadFileToString(
         test_data_dir_.AppendASCII("extension_resource_request_policy")
             .AppendASCII("index.html"),
diff --git a/chrome/browser/extensions/extension_webui_apitest.cc b/chrome/browser/extensions/extension_webui_apitest.cc
index 3c234a71..cf6cf5c 100644
--- a/chrome/browser/extensions/extension_webui_apitest.cc
+++ b/chrome/browser/extensions/extension_webui_apitest.cc
@@ -37,7 +37,7 @@
                                    bool expected_result) {
     std::string script;
     {
-      base::ThreadRestrictions::ScopedAllowIO allow_io;
+      base::ScopedAllowBlockingForTesting allow_blocking;
       // Tests are located in chrome/test/data/extensions/webui/$(name).
       base::FilePath path;
       PathService::Get(chrome::DIR_TEST_DATA, &path);
diff --git a/chrome/browser/extensions/lazy_background_page_apitest.cc b/chrome/browser/extensions/lazy_background_page_apitest.cc
index ec3a48dd..a169bdd 100644
--- a/chrome/browser/extensions/lazy_background_page_apitest.cc
+++ b/chrome/browser/extensions/lazy_background_page_apitest.cc
@@ -327,7 +327,7 @@
 IN_PROC_BROWSER_TEST_F(LazyBackgroundPageApiTest, NaClInBackgroundPage) {
   {
     base::FilePath extdir;
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::Get(chrome::DIR_GEN_TEST_DATA, &extdir));
     extdir = extdir.AppendASCII("ppapi/tests/extensions/load_unload/newlib");
     LazyBackgroundObserver page_complete;
@@ -364,7 +364,7 @@
   // page, and the Lazy Background Page stays alive.
   {
     base::FilePath extdir;
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     ASSERT_TRUE(PathService::Get(chrome::DIR_GEN_TEST_DATA, &extdir));
     extdir = extdir.AppendASCII("ppapi/tests/extensions/popup/newlib");
     ResultCatcher catcher;
diff --git a/chrome/browser/extensions/service_worker_apitest.cc b/chrome/browser/extensions/service_worker_apitest.cc
index c594d7b..1b738d8 100644
--- a/chrome/browser/extensions/service_worker_apitest.cc
+++ b/chrome/browser/extensions/service_worker_apitest.cc
@@ -337,7 +337,7 @@
 }
 
 IN_PROC_BROWSER_TEST_P(ServiceWorkerTest, UpdateRefreshesServiceWorker) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   ASSERT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.AppendASCII("service_worker")
@@ -379,7 +379,7 @@
 
 // TODO(crbug.com/765736) Fix the test.
 IN_PROC_BROWSER_TEST_P(ServiceWorkerTest, DISABLED_UpdateWithoutSkipWaiting) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   base::ScopedTempDir scoped_temp_dir;
   ASSERT_TRUE(scoped_temp_dir.CreateUniqueTempDir());
   base::FilePath pem_path = test_data_dir_.AppendASCII("service_worker")
diff --git a/chrome/browser/extensions/startup_helper_browsertest.cc b/chrome/browser/extensions/startup_helper_browsertest.cc
index 36fcc36..8f7807d4 100644
--- a/chrome/browser/extensions/startup_helper_browsertest.cc
+++ b/chrome/browser/extensions/startup_helper_browsertest.cc
@@ -50,7 +50,7 @@
 
     std::string error;
     extensions::StartupHelper helper;
-    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    base::ScopedAllowBlockingForTesting allow_blocking;
     bool result = helper.ValidateCrx(command_line, &error);
     if (i->second) {
       EXPECT_TRUE(result) << path.LossyDisplayName()
diff --git a/chrome/browser/extensions/test_extension_dir.cc b/chrome/browser/extensions/test_extension_dir.cc
index daf2c76..18dc45a 100644
--- a/chrome/browser/extensions/test_extension_dir.cc
+++ b/chrome/browser/extensions/test_extension_dir.cc
@@ -16,13 +16,13 @@
 namespace extensions {
 
 TestExtensionDir::TestExtensionDir() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   EXPECT_TRUE(dir_.CreateUniqueTempDir());
   EXPECT_TRUE(crx_dir_.CreateUniqueTempDir());
 }
 
 TestExtensionDir::~TestExtensionDir() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ignore_result(dir_.Delete());
   ignore_result(crx_dir_.Delete());
 }
@@ -40,7 +40,7 @@
 
 void TestExtensionDir::WriteFile(const base::FilePath::StringType& filename,
                                  base::StringPiece contents) {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   EXPECT_EQ(base::checked_cast<int>(contents.size()),
             base::WriteFile(dir_.GetPath().Append(filename), contents.data(),
                             contents.size()));
@@ -49,7 +49,7 @@
 // This function packs the extension into a .crx, and returns the path to that
 // .crx. Multiple calls to Pack() will produce extensions with the same ID.
 base::FilePath TestExtensionDir::Pack() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   ExtensionCreator creator;
   base::FilePath crx_path =
       crx_dir_.GetPath().Append(FILE_PATH_LITERAL("ext.crx"));
@@ -74,7 +74,7 @@
 }
 
 base::FilePath TestExtensionDir::UnpackedPath() {
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
+  base::ScopedAllowBlockingForTesting allow_blocking;
   // We make this absolute because it's possible that dir_ contains a symlink as
   // part of it's path. When UnpackedInstaller::GetAbsolutePath() runs as part
   // of loading the extension, the extension's path is converted to an absolute