Fix browser launch on the login screen.

ui/web_dialogs/web_dialog_delegate.cc

 // 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.
 
 #include "ui/web_dialogs/web_dialog_delegate.h"
 
 namespace ui {
 
 std::string WebDialogDelegate::GetDialogName() const {
   return std::string();
@@ skipping 30 matching lines @@
 
 bool WebDialogDelegate::HandleAddNewContents(
     content::WebContents* source,
     content::WebContents* new_contents,
     WindowOpenDisposition disposition,
     const gfx::Rect& initial_pos,
     bool user_gesture) {
   return false;
 }
 
+bool WebDialogDelegate::HandleShouldCreateWebContents() {
+  return true;
+}
+
 }  // namespace ui