Make win_aura work without ash.

ui/aura/root_window_host.h

 // 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.
 
 #ifndef UI_AURA_ROOT_WINDOW_HOST_H_
 #define UI_AURA_ROOT_WINDOW_HOST_H_
 #pragma once
 
 #include "base/message_loop.h"
 #include "ui/base/cursor/cursor.h"
@@ skipping 16 matching lines @@
  public:
   virtual ~RootWindowHost() {}
 
   // Creates a new RootWindowHost. The caller owns the returned value.
   static RootWindowHost* Create(const gfx::Rect& bounds);
 
   // Returns the actual size of the screen.
   // (gfx::Screen only reports on the virtual desktop exposed by Aura.)
   static gfx::Size GetNativeScreenSize();
 
+  // Returns the RootWindowHost for the specified accelerated widget, or NULL if
+  // there is none associated.
+  static RootWindowHost* GetForAcceleratedWidget(
+      gfx::AcceleratedWidget accelerated_widget);
+
   // Sets the RootWindow this RootWindowHost is hosting. RootWindowHost does not
   // own the RootWindow.
   virtual void SetRootWindow(RootWindow* root_window) = 0;
+  virtual RootWindow* GetRootWindow() = 0;
 
   // Returns the accelerated widget.
   virtual gfx::AcceleratedWidget GetAcceleratedWidget() = 0;
 
   // Shows the RootWindowHost.
   virtual void Show() = 0;
 
   // Toggles the host's full screen state.
   virtual void ToggleFullScreen() = 0;
 
@@ skipping 34 matching lines @@
 
   // Posts |native_event| to the platform's event queue.
 #if !defined(OS_MACOSX)
   virtual void PostNativeEvent(const base::NativeEvent& native_event) = 0;
 #endif
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_ROOT_WINDOW_HOST_H_