aura: Use PlatformWindow from WindowTreeHost.

ui/aura/window_tree_host_ozone.h

 // 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.
 
 #ifndef UI_AURA_WINDOW_TREE_HOST_OZONE_H_
 #define UI_AURA_WINDOW_TREE_HOST_OZONE_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/events/event_source.h"
@@ skipping 17 matching lines @@
   // ui::PlatformWindowDelegate:
   virtual void OnBoundsChanged(const gfx::Rect&) OVERRIDE;
   virtual void OnDamageRect(const gfx::Rect& damaged_region) OVERRIDE;
   virtual void DispatchEvent(ui::Event* event) OVERRIDE;
   virtual void OnCloseRequest() OVERRIDE;
   virtual void OnClosed() OVERRIDE;
   virtual void OnWindowStateChanged(ui::PlatformWindowState new_state) OVERRIDE;
   virtual void OnLostCapture() OVERRIDE;
   virtual void OnAcceleratedWidgetAvailable(
       gfx::AcceleratedWidget widget) OVERRIDE;
+  virtual void OnActivationChanged(bool active) OVERRIDE;
 
   // WindowTreeHost:
   virtual ui::EventSource* GetEventSource() OVERRIDE;
   virtual gfx::AcceleratedWidget GetAcceleratedWidget() OVERRIDE;
   virtual void Show() OVERRIDE;
   virtual void Hide() OVERRIDE;
   virtual gfx::Rect GetBounds() const OVERRIDE;
   virtual void SetBounds(const gfx::Rect& bounds) OVERRIDE;
   virtual gfx::Point GetLocationOnNativeScreen() const OVERRIDE;
   virtual void SetCapture() OVERRIDE;
@@ skipping 11 matching lines @@
 
   // The identifier used to create a compositing surface.
   gfx::AcceleratedWidget widget_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostOzone);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_TREE_HOST_OZONE_H_