Makes copying layers clone external textures.

ui/aura/window_delegate.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_WINDOW_DELEGATE_H_
 #define UI_AURA_WINDOW_DELEGATE_H_
 
 #include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
 #include "ui/aura/aura_export.h"
 #include "ui/base/events/event_constants.h"
 #include "ui/base/events/event_handler.h"
 #include "ui/gfx/native_widget_types.h"
 
 namespace gfx {
 class Canvas;
 class Path;
 class Point;
 class Rect;
 class Size;
 }
 
 namespace ui {
 class GestureEvent;
 class KeyEvent;
 class MouseEvent;
+class Texture;
 class TouchEvent;
 }
 
 namespace aura {
 
 // Delegate interface for aura::Window.
 class AURA_EXPORT WindowDelegate : public ui::EventHandler {
  public:
   // Returns the window's minimum size, or size 0,0 if there is no limit.
   virtual gfx::Size GetMinimumSize() const = 0;
@@ skipping 51 matching lines @@
   // Called from Window::HitTest to check if the window has a custom hit test
   // mask. It works similar to the views counterparts. That is, if the function
   // returns true, GetHitTestMask below will be called to get the mask.
   // Otherwise, Window will hit-test against its bounds.
   virtual bool HasHitTestMask() const = 0;
 
   // Called from Window::HitTest to retrieve hit test mask when HasHitTestMask
   // above returns true.
   virtual void GetHitTestMask(gfx::Path* mask) const = 0;
 
+  // Called from RecreateLayer() if the layer the window is associated with has
+  // an external texture.
+  virtual scoped_refptr<ui::Texture> CopyTexture() = 0;
+
  protected:
   virtual ~WindowDelegate() {}
 
   // Overridden from ui::EventHandler:
   virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_WINDOW_DELEGATE_H_