Reland "Use the same browser instance in the sync confirmation dialog.

chrome/browser/ui/webui/signin/sync_confirmation_handler.h

 // Copyright 2015 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 CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_
 
 #include <string>
 
 #include "base/macros.h"
+#include "chrome/browser/ui/browser_list_observer.h"
 #include "chrome/browser/ui/webui/signin/login_ui_service.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 namespace base {
 class ListValue;
 }
 
 class SyncConfirmationHandler : public content::WebUIMessageHandler,
-                                public AccountTrackerService::Observer {
+                                public AccountTrackerService::Observer,
+                                public chrome::BrowserListObserver {
  public:
-  SyncConfirmationHandler();
+  explicit SyncConfirmationHandler(Browser* browser);
   ~SyncConfirmationHandler() override;
 
   // content::WebUIMessageHandler:
   void RegisterMessages() override;
 
   // AccountTrackerService::Observer:
   void OnAccountUpdated(const AccountInfo& info) override;
 
+  // chrome::BrowserListObserver:
+  void OnBrowserRemoved(Browser* browser) override;
+
  protected:
   // Handles "confirm" message from the page. No arguments.
   // This message is sent when the user confirms that they want complete sign in
   // with default sync settings.
   virtual void HandleConfirm(const base::ListValue* args);
 
   // Handles "undo" message from the page. No arguments.
   // This message is sent when the user clicks "undo" on the sync confirmation
   // dialog, which aborts signin and prevents sync from starting.
   virtual void HandleUndo(const base::ListValue* args);
@@ skipping 12 matching lines @@
   // Sets the profile picture shown in the dialog to the image at |url|.
   virtual void SetUserImageURL(const std::string& url);
 
   // Closes the modal signin window and calls
   // LoginUIService::SyncConfirmationUIClosed with |result|. |result| indicates
   // the option chosen by the user in the confirmation UI.
   void CloseModalSigninWindow(
       LoginUIService::SyncConfirmationUIClosedResult result);
 
  private:
+  Profile* profile_;
+
+  // Weak reference to the browser that showed the sync confirmation dialog.
+  Browser* browser_;
+
   // Records whether the user clicked on Undo, Ok, or Settings.
   bool did_user_explicitly_interact;
 
   DISALLOW_COPY_AND_ASSIGN(SyncConfirmationHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_SYNC_CONFIRMATION_HANDLER_H_