ExtensionService: Delay non-critical IO until after startup has finished.

chrome/browser/extensions/extension_service.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 
 #include <list>
 #include <map>
 #include <set>
@@ skipping 362 matching lines @@
 
   // Updates the |extension|'s granted permissions lists to include all
   // permissions in the |extensions|'s manifest.
   void GrantPermissions(
       const extensions::Extension* extension,
       bool record_oauth2_grant);
 
   // Check for updates (or potentially new extensions from external providers)
   void CheckForExternalUpdates();
 
+  // For testing: CheckForExternalUpdates() is idempotent.  Reset the flag
+  // that causes the function to perform an early return after it's first
+  // invocation.
+  void ResetExternalUpdateCheckGuardForTests() {
+    external_update_check_has_run_ = false;
+  }
+
   // Unload the specified extension.
   virtual void UnloadExtension(
       const std::string& extension_id,
       extension_misc::UnloadedExtensionReason reason) OVERRIDE;
 
   // Unload all extensions. This is currently only called on shutdown, and
   // does not send notifications.
   void UnloadAllExtensions();
 
   // Called only by testing.
@@ skipping 494 matching lines @@
   // idle.
   bool install_updates_when_idle_;
 
   // Used by dispatchers to limit API quota for individual extensions.
   ExtensionsQuotaService quota_service_;
 
   // Record that Init() has been called, and chrome::EXTENSIONS_READY
   // has fired.
   bool ready_;
 
+  // Have we done an external update check yet?
+  bool external_update_check_has_run_;
+
   // Our extension updater, if updates are turned on.
   scoped_ptr<extensions::ExtensionUpdater> updater_;
 
   // The model that tracks extensions with BrowserAction buttons.
   ExtensionToolbarModel toolbar_model_;
 
   // Map unloaded extensions' ids to their paths. When a temporarily loaded
   // extension is unloaded, we lose the information about it and don't have
   // any in the extension preferences file.
   typedef std::map<std::string, FilePath> UnloadedExtensionPathMap;
@@ skipping 101 matching lines @@
 #endif
 
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsWithUnlimtedStorage);
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsAndCheckStorageProtection);
   DISALLOW_COPY_AND_ASSIGN(ExtensionService);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_