Eliminate ProfileOAuth2TokenService being a BCKS.

chrome/browser/signin/profile_oauth2_token_service_factory.h

Index: chrome/browser/signin/profile_oauth2_token_service_factory.h
diff --git a/chrome/browser/signin/profile_oauth2_token_service_factory.h b/chrome/browser/signin/profile_oauth2_token_service_factory.h
index a5204786b52c13771f2173da9dd34990317f2480..ab58937b3f5325808dab9ab457fe83e0b91b7d39 100644
--- a/chrome/browser/signin/profile_oauth2_token_service_factory.h
+++ b/chrome/browser/signin/profile_oauth2_token_service_factory.h
@@ -17,7 +17,13 @@ class AndroidProfileOAuth2TokenService;
 class MutableProfileOAuth2TokenService;
 #endif
 
-// Singleton that owns all ProfileOAuth2TokenServices and associates them with
+// A wrapper of ProfileOAuth2TokenService so we can use it as a BCKS.
+class ProfileOAuth2TokenServiceWrapper : public BrowserContextKeyedService {
+ public:
+  virtual ProfileOAuth2TokenService* GetProfileOAuth2TokenService() = 0;
+};
+
+/// Singleton that owns all ProfileOAuth2TokenServices and associates them with
 // Profiles. Listens for the Profile's destruction notification and cleans up
 // the associated ProfileOAuth2TokenService.
 class ProfileOAuth2TokenServiceFactory
@@ -46,6 +52,7 @@ class ProfileOAuth2TokenServiceFactory
 
  private:
   friend struct DefaultSingletonTraits<ProfileOAuth2TokenServiceFactory>;
+  friend class ProfileOAuth2TokenServiceWrapperImpl;
 
 #if defined(OS_ANDROID)
   typedef AndroidProfileOAuth2TokenService PlatformSpecificOAuth2TokenService;