Fix app_shell shutdown crash due to BrowserContextKeyedServices

chrome/browser/chromeos/drive/drive_integration_service.h

Index: chrome/browser/chromeos/drive/drive_integration_service.h
diff --git a/chrome/browser/chromeos/drive/drive_integration_service.h b/chrome/browser/chromeos/drive/drive_integration_service.h
index 2f6dd45c30978893135fd32ad38f00d939e039d9..dac74ff925e77684e15572e4d1cf6412be9620f2 100644
--- a/chrome/browser/chromeos/drive/drive_integration_service.h
+++ b/chrome/browser/chromeos/drive/drive_integration_service.h
@@ -185,8 +185,8 @@ 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.
@@ -208,7 +208,7 @@ class DriveIntegrationServiceFactory
   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>;
@@ -220,7 +220,10 @@ class DriveIntegrationServiceFactory
   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