Make sure GetAuthenticatedAccountId() returns a canonicalized id.

components/signin/core/browser/signin_manager_base.h

 // Copyright 2014 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.
 //
 // The signin manager encapsulates some functionality tracking
 // which user is signed in.
 //
 // **NOTE** on semantics of SigninManager:
 //
 // Once a signin is successful, the username becomes "established" and will not
@@ skipping 107 matching lines @@
   // Methods to register or remove SigninDiagnosticObservers.
   void AddSigninDiagnosticsObserver(
       signin_internals_util::SigninDiagnosticsObserver* observer);
   void RemoveSigninDiagnosticsObserver(
       signin_internals_util::SigninDiagnosticsObserver* observer);
 
  protected:
   // Used by subclass to clear authenticated_username_ instead of using
   // SetAuthenticatedUsername, which enforces special preconditions due
   // to the fact that it is part of the public API and called by clients.
-  void clear_authenticated_username();
+  void ClearAuthenticatedUsername();
 
   // List of observers to notify on signin events.
   // Makes sure list is empty on destruction.
   ObserverList<Observer, true> observer_list_;
 
   // Helper methods to notify all registered diagnostics observers with.
   void NotifyDiagnosticsObservers(
       const signin_internals_util::UntimedSigninStatusField& field,
       const std::string& value);
   void NotifyDiagnosticsObservers(
       const signin_internals_util::TimedSigninStatusField& field,
       const std::string& value);
 
  private:
   friend class FakeSigninManagerBase;
   friend class FakeSigninManager;
 
   SigninClient* client_;
   bool initialized_;
 
-  // Actual username after successful authentication.
+  // Actual username and account_id after successful authentication.
   std::string authenticated_username_;
+  std::string authenticated_account_id_;
 
   // The list of SigninDiagnosticObservers.
   ObserverList<signin_internals_util::SigninDiagnosticsObserver, true>
       signin_diagnostics_observers_;
 
   base::WeakPtrFactory<SigninManagerBase> weak_pointer_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninManagerBase);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_SIGNIN_MANAGER_BASE_H_