[Signin Error Dialog] (3/3) Added the triggering code

chrome/browser/ui/webui/signin/login_ui_service.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 CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_
 #define CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_
 
 #include <list>
 
 #include "base/macros.h"
@@ skipping 62 matching lines @@
   // Called when the sync confirmation UI is closed. |result| indicates the
   // option chosen by the user in the confirmation UI.
   void SyncConfirmationUIClosed(SyncConfirmationUIClosedResult result);
 
   // Delegate to an existing login dialog if one exists.
   // If not, we make a new popup dialog window, and set it to
   // chrome://signin to ask the user to sign in to chrome.
   void ShowLoginPopup();
 
   // Displays login results.
-  void DisplayLoginResult(Browser* browser, const base::string16& message);
+  void DisplayLoginResult(Browser* browser,

[tommycli, 2016/09/20 17:48:05]

I assume this displays a "success" dialog if there's an empty error_message and
an "error" dialog if it's populated? If so, can we add a bit of explanatory
comments?

[anthonyvd, 2016/09/21 15:07:24]

Done.

+                          const base::string16& error_message,
+                          const base::string16& email);
 
   // Gets the last login result set through |DisplayLoginResult|.
   const base::string16& GetLastLoginResult() const;
 
   // Gets the last email used for signing in when a signin error occured; set
   // through |DisplayLoginResult|.
   const base::string16& GetLastLoginErrorEmail() const;
 
  private:
   // Weak pointers to the recently opened UIs, with the most recent in front.
   std::list<LoginUI*> ui_list_;
 #if !defined(OS_CHROMEOS)
   Profile* profile_;
 #endif
 
   // List of observers.
   base::ObserverList<Observer> observer_list_;
 
   base::string16 last_login_result_;
   base::string16 last_login_error_email_;
 
   DISALLOW_COPY_AND_ASSIGN(LoginUIService);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_LOGIN_UI_SERVICE_H_