Add a full screen virtual keyboard to virtual keyboard root window

ash/keyboard_controller_proxy_stub.cc

 // Copyright 2013 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/keyboard_controller_proxy_stub.h"
 
 #include "ash/shell.h"
+#include "ui/aura/window.h"
 #include "ui/views/corewm/input_method_event_filter.h"
 
 using namespace content;
 
 namespace ash {
 
 KeyboardControllerProxyStub::KeyboardControllerProxyStub() {
 }
 
 KeyboardControllerProxyStub::~KeyboardControllerProxyStub() {
 }
 
+aura::Window* KeyboardControllerProxyStub::GetKeyboardWindow() {
+  aura::Window* window = new aura::Window(&delegate_);
+  window->Init(ui::LAYER_NOT_DRAWN);
+  return window;
+}
+
 BrowserContext* KeyboardControllerProxyStub::GetBrowserContext() {
   return Shell::GetInstance()->browser_context();
 }
 
 ui::InputMethod* KeyboardControllerProxyStub::GetInputMethod() {
   return Shell::GetInstance()->input_method_filter()->input_method();
 }
 
 void KeyboardControllerProxyStub::RequestAudioInput(
     WebContents* web_contents,
     const MediaStreamRequest& request,
     const MediaResponseCallback& callback) {
 }
 
 }  // namespace ash