Ensure IsExtensionEnabled functions for non-installed extensions.

BUG=437715

Review URL: https://codereview.chromium.org/741643004

Cr-Commit-Position: refs/heads/master@{#306283}
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index 59f31db..17cb2d8b 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -3769,6 +3769,15 @@
   ASSERT_TRUE(IsBlocked(good0));
 }
 
+// Tests that IsEnabledExtension won't crash on an uninstalled extension.
+TEST_F(ExtensionServiceTest, IsEnabledExtensionBlockedAndNotInstalled) {
+  InitializeEmptyExtensionService();
+
+  service()->BlockAllExtensions();
+
+  service()->IsExtensionEnabled(theme_crx);
+}
+
 // Will not install extension blacklisted by policy.
 TEST_F(ExtensionServiceTest, BlacklistedByPolicyWillNotInstall) {
   InitializeEmptyExtensionServiceWithTestingPrefs();