Support "Report Issue" in case of no-browser windows in ChromeOS.

ash/shell/shell_delegate_impl.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 "ash/shell/shell_delegate_impl.h"
 
 #include "ash/shell/example_factory.h"
 #include "ash/shell/launcher_delegate_impl.h"
 #include "ash/shell/toplevel_window.h"
 #include "ash/shell_window_ids.h"
@@ skipping 106 matching lines @@
 }
 
 ash::SystemTrayDelegate* ShellDelegateImpl::CreateSystemTrayDelegate(
     ash::SystemTray* tray) {
   return NULL;
 }
 
 ash::UserWallpaperDelegate* ShellDelegateImpl::CreateUserWallpaperDelegate() {
   return NULL;
 }
+
 aura::client::UserActionClient* ShellDelegateImpl::CreateUserActionClient() {
   return NULL;
 }
 
+void ShellDelegateImpl::OpenFeedbackPage() {
+}
+
 }  // namespace shell
 }  // namespace ash