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

chrome/browser/ui/cocoa/profiles/signin_view_controller_delegate_mac.h

 // Copyright 2016 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_COCOA_PROFILES_SIGNIN_VIEW_CONTROLLER_DELEGATE_MAC_H_
 #define CHROME_BROWSER_UI_COCOA_PROFILES_SIGNIN_VIEW_CONTROLLER_DELEGATE_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
@@ skipping 40 matching lines @@
   // |profile| as the web content's profile, then sets |delegate| as the created
   // web content's delegate.
   static std::unique_ptr<content::WebContents> CreateGaiaWebContents(
       content::WebContentsDelegate* delegate,
       profiles::BubbleViewMode mode,
       Profile* profile,
       signin_metrics::AccessPoint access_point);
 
   static std::unique_ptr<content::WebContents>
   CreateSyncConfirmationWebContents(Profile* profile);
+  CreateSigninErrorWebContents(Profile* profile);
 
  private:
   void PerformClose() override;
   void ResizeNativeView(int height) override;
 
   void DisplayModal();
 
   void HandleKeyboardEvent(
       content::WebContents* source,
       const content::NativeWebKeyboardEvent& event) override;
@@ skipping 15 matching lines @@
 
   // The web contents that the constrained window is displayed off of.
   // Typically, this is going to be the active tab when the window is shown.
   content::WebContents* host_web_contents_;
   NSRect window_frame_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninViewControllerDelegateMac);
 };
 
 #endif  // CHROME_BROWSER_UI_COCOA_PROFILES_SIGNIN_VIEW_CONTROLLER_DELEGATE_MAC_H_