Handle multiple signin_internal_uis by using a linked_ptr

components/signin/core/browser/about_signin_internals.h

 // Copyright (c) 2012 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.
 
 #ifndef COMPONENTS_SIGNIN_CORE_BROWSER_ABOUT_SIGNIN_INTERNALS_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_ABOUT_SIGNIN_INTERNALS_H_
 
 #include <map>
 #include <string>
 
+#include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/values.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/signin/core/browser/signin_client.h"
 #include "components/signin/core/browser/signin_internals_util.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "google_apis/gaia/gaia_auth_consumer.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
@@ skipping 16 matching lines @@
  public:
   class Observer {
    public:
     // |info| will contain the dictionary of signin_status_ values as indicated
     // in the comments for GetSigninStatus() below.
     virtual void OnSigninStateChanged(
         scoped_ptr<base::DictionaryValue> info) = 0;
 
     // Notification that the cookie accounts are ready to be displayed.
     virtual void OnCookieAccountsFetched(
-        scoped_ptr<base::DictionaryValue> info) = 0;
+        linked_ptr<base::DictionaryValue> info) = 0;
   };
 
   AboutSigninInternals(ProfileOAuth2TokenService* token_service,
                        SigninManagerBase* signin_manager);
   virtual ~AboutSigninInternals();
 
   // Each instance of SigninInternalsUI adds itself as an observer to be
   // notified of all updates that AboutSigninInternals receives.
   void AddSigninObserver(Observer* observer);
   void RemoveSigninObserver(Observer* observer);
@@ skipping 148 matching lines @@
 
   ObserverList<Observer> signin_observers_;
 
   scoped_ptr<SigninClient::CookieChangedCallbackList::Subscription>
       cookie_changed_subscription_;
 
   DISALLOW_COPY_AND_ASSIGN(AboutSigninInternals);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_ABOUT_SIGNIN_INTERNALS_H_