make StackingClient dispatch to either ash or desktop

ui/aura/desktop/desktop_stacking_client.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_DESKTOP_DESKTOP_STACKING_CLIENT_H_
 #define UI_AURA_DESKTOP_DESKTOP_STACKING_CLIENT_H_
 
 #include "ui/aura/client/stacking_client.h"
 
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
 }
 
 // A stacking client for the desktop; always sets the default parent to the
 // RootWindow of the passed in Window.
 class VIEWS_EXPORT DesktopStackingClient : public client::StackingClient {
  public:
   DesktopStackingClient();
   virtual ~DesktopStackingClient();
 
   // Overridden from client::StackingClient:
-  virtual Window* GetDefaultParent(Window* window,
+  virtual Window* GetDefaultParent(Window* context,
+                                   Window* window,
                                    const gfx::Rect& bounds) OVERRIDE;
 
  private:
   // Windows with NULL parents are parented to this.
   scoped_ptr<aura::RootWindow> null_parent_;
 
   scoped_ptr<aura::client::DefaultCaptureClient> capture_client_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopStackingClient);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_DESKTOP_DESKTOP_STACKING_CLIENT_H_