Move SigninTracker away from listening for SigninManager notifications

chrome/browser/signin/signin_tracker.h

Index: chrome/browser/signin/signin_tracker.h
diff --git a/chrome/browser/signin/signin_tracker.h b/chrome/browser/signin/signin_tracker.h
index 351c086c2bdb6141faeb3ae381766a05ed4e26a7..69dbcc347464613145af3a74f3776af990caf5fc 100644
--- a/chrome/browser/signin/signin_tracker.h
+++ b/chrome/browser/signin/signin_tracker.h
@@ -6,9 +6,7 @@
 #define CHROME_BROWSER_SIGNIN_SIGNIN_TRACKER_H_
 
 #include "base/memory/scoped_ptr.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "content/public/browser/notification_types.h"
+#include "chrome/browser/signin/signin_manager_base.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "google_apis/gaia/merge_session_helper.h"
 #include "google_apis/gaia/oauth2_token_service.h"
@@ -48,7 +46,7 @@ class Profile;
 // sync framework. Listens for notifications for tokens to know when to startup
 // sync, and provides an Observer interface to notify the UI layer of changes
 // in sync state so they can be reflected in the UI.
-class SigninTracker : public content::NotificationObserver,
+class SigninTracker : public SigninManagerBase::Observer,
                       public OAuth2TokenService::Observer,
                       public MergeSessionHelper::Observer {
  public:
@@ -71,10 +69,8 @@ class SigninTracker : public content::NotificationObserver,
   SigninTracker(Profile* profile, Observer* observer);
   virtual ~SigninTracker();
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // SigninManagerBase::Observer implementation.
+  virtual void GoogleSigninFailed(const GoogleServiceAuthError& error) OVERRIDE;
 
   // OAuth2TokenService::Observer implementation.
   virtual void OnRefreshTokenAvailable(const std::string& account_id) OVERRIDE;
@@ -95,9 +91,6 @@ class SigninTracker : public content::NotificationObserver,
   // Weak pointer to the observer we call when the signin state changes.
   Observer* observer_;
 
-  // Used to listen to notifications from the SigninManager.
-  content::NotificationRegistrar registrar_;
-
   DISALLOW_COPY_AND_ASSIGN(SigninTracker);
 };