Fix app_shell shutdown crash due to BrowserContextKeyedServices

chrome/browser/chromeos/drive/drive_integration_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_CHROMEOS_DRIVE_DRIVE_INTEGRATION_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_INTEGRATION_SERVICE_H_
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
@@ skipping 167 matching lines @@
   base::WeakPtrFactory<DriveIntegrationService> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(DriveIntegrationService);
 };
 
 // Singleton that owns all instances of DriveIntegrationService and
 // associates them with Profiles.
 class DriveIntegrationServiceFactory
     : public BrowserContextKeyedServiceFactory {
  public:
   // Factory function used by tests.
-  typedef base::Callback<DriveIntegrationService*(Profile* profile)>
-      FactoryCallback;
+  typedef DriveIntegrationService*(FactoryFunction)(Profile* profile,
+                                                    void* data);
 
   // Returns the DriveIntegrationService for |profile|, creating it if it is
   // not yet created.
   static DriveIntegrationService* GetForProfile(Profile* profile);
 
   // Same as GetForProfile. TODO(hidehiko): Remove this.
   static DriveIntegrationService* GetForProfileRegardlessOfStates(
       Profile* profile);
 
   // Returns the DriveIntegrationService that is already associated with
   // |profile|, if it is not yet created it will return NULL.
   static DriveIntegrationService* FindForProfile(Profile* profile);
 
   // Same as FindForProfile. TODO(hidehiko): Remove this.
   static DriveIntegrationService* FindForProfileRegardlessOfStates(
       Profile* profile);
 
   // Returns the DriveIntegrationServiceFactory instance.
   static DriveIntegrationServiceFactory* GetInstance();
 
   // Sets a factory function for tests.
-  static void SetFactoryForTest(const FactoryCallback& factory_for_test);
+  static void SetFactoryForTest(FactoryFunction factory_for_test, void* data);
 
  private:
   friend struct DefaultSingletonTraits<DriveIntegrationServiceFactory>;
 
   DriveIntegrationServiceFactory();
   virtual ~DriveIntegrationServiceFactory();
 
   // BrowserContextKeyedServiceFactory:
   virtual BrowserContextKeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const OVERRIDE;
 
-  FactoryCallback factory_for_test_;
+  // These are static so we can delay creating an instance of this factory
+  // (and all its dependent factories) until the profile is created.

[tbarzic, 2014/01/09 01:58:25]

nit: What do you think about slightly more context here:

These are static so they can be set without instantiating the factory. This
makes it possible to delay factory creation until it normally happens (on
profile creation) rather than when tests are set up.
DriveIntegrationServiceFactory transitively depends on ExtensionSystemFactory
which crashes if created too soon (i.e. before browser process exists).

[James Cook, 2014/01/09 17:32:19]

That's a much better comment. Done.

+  static FactoryFunction* factory_function_for_test_;
+  static void* factory_data_for_test_;
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_INTEGRATION_SERVICE_H_