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

chrome/browser/ui/signin_view_controller_delegate.h

Index: chrome/browser/ui/signin_view_controller_delegate.h
diff --git a/chrome/browser/ui/signin_view_controller_delegate.h b/chrome/browser/ui/signin_view_controller_delegate.h
index 445a60f4357c7f78083ebcc552cb93bc77de022c..c4f4cd361a59637a7b473751523a8de85b0b8a29 100644
--- a/chrome/browser/ui/signin_view_controller_delegate.h
+++ b/chrome/browser/ui/signin_view_controller_delegate.h
@@ -24,16 +24,29 @@ enum class AccessPoint;
 // managing closes.
 class SigninViewControllerDelegate : public content::WebContentsDelegate {
  public:
+  // Returns a platform-specific SigninViewControllerDelegate instance that
+  // displays the sign in flow. The returned object should delete itself when
+  // the window it's managing is closed.
   static SigninViewControllerDelegate* CreateModalSigninDelegate(
       SigninViewController* signin_view_controller,
       profiles::BubbleViewMode mode,
       Browser* browser,
       signin_metrics::AccessPoint access_point);
 
+  // Returns a platform-specific SigninViewControllerDelegate instance that
+  // displays the sync confirmation dialog. The returned object should delete
+  // itself when the window it's managing is closed.
   static SigninViewControllerDelegate* CreateSyncConfirmationDelegate(
       SigninViewController* signin_view_controller,
       Browser* browser);
 
+  // Returns a platform-specific SigninViewControllerDelegate instance that
+  // displays the modal sign in error dialog. The returned object should delete
+  // itself when the window it's managing is closed.
+  static SigninViewControllerDelegate* CreateSigninErrorDelegate(
+      SigninViewController* signin_view_controller,
+      Browser* browser);
+
   void CloseModalSignin();
 
   // Either navigates back in the signin flow if the history state allows it or