Add account_id to signin manager notifications.

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 30 matching lines @@
 class SigninClient;
 
 class SigninManagerBase : public KeyedService {
  public:
   class Observer {
    public:
     // Called when a user fails to sign into Google services such as sync.
     virtual void GoogleSigninFailed(const GoogleServiceAuthError& error) {}
 
     // Called when a user signs into Google services such as sync.
-    virtual void GoogleSigninSucceeded(const std::string& username,
+    virtual void GoogleSigninSucceeded(const std::string& account_id,
+                                       const std::string& username,
                                        const std::string& password) {}
 
     // Called when the currently signed-in user for a user has been signed out.
-    virtual void GoogleSignedOut(const std::string& username) {}
+    virtual void GoogleSignedOut(const std::string& account_id,
+                                 const std::string& username) {}

[guohui, 2014/08/27 17:57:42]

Why have both account_id and username in the signature? account_id is supposed
to uniquely identify a user and it could always be converted to username using
AccountTrackerService when necessary. So isn't it cleaner to have account_id
only?

[Roger Tawa OOO till Jul 10th, 2014/08/27 18:51:01]

Because that would require observers to keep a pointer to the Profile* so that
they could access AccountTrackerService.  In one case that does not happen
(SigninNamesOnIOThread).  Also, I think its better to pass both to the event
than have one come in as an arg and the other have to be fetched from a PKS.

 
    protected:
     virtual ~Observer() {}
   };
 
   SigninManagerBase(SigninClient* client);
   virtual ~SigninManagerBase();
 
   // If user was signed in, load tokens from DB if available.
   virtual void Initialize(PrefService* local_state);
@@ skipping 84 matching lines @@
   // 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_