Makes copying layers clone external textures.

ui/compositor/layer.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_COMPOSITOR_LAYER_H_
 #define UI_COMPOSITOR_LAYER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 202 matching lines @@
   bool fills_bounds_opaquely() const { return fills_bounds_opaquely_; }
 
   const std::string& name() const { return name_; }
   void set_name(const std::string& name) { name_ = name; }
 
   const ui::Texture* texture() const { return texture_.get(); }
 
   // Assigns a new external texture.  |texture| can be NULL to disable external
   // updates.
   void SetExternalTexture(ui::Texture* texture);
+  ui::Texture* external_texture() { return texture_.get(); }
 
   // Sets the layer's fill color.  May only be called for LAYER_SOLID_COLOR.
   void SetColor(SkColor color);
 
   // Adds |invalid_rect| to the Layer's pending invalid rect and calls
   // ScheduleDraw(). Returns false if the paint request is ignored.
   bool SchedulePaint(const gfx::Rect& invalid_rect);
 
   // Schedules a redraw of the layer tree at the compositor.
   // Note that this _does not_ invalidate any region of this layer; use
@@ skipping 159 matching lines @@
 
   // A cached copy of |Compositor::device_scale_factor()|.
   float device_scale_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_