aura: Use Layer::SetShowPaintedContent to stop showing external content

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 255 matching lines @@
                          gfx::Size frame_size_in_dip);
 
   bool has_external_content() {
     return texture_layer_.get() || delegated_renderer_layer_.get();
   }
 
   // Gets unused resources to recycle to the child compositor.
   void TakeUnusedResourcesForChildCompositor(
       cc::ReturnedResourceArray* array);
 
+  void SetShowPaintedContent();
+
   // 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
   // SchedulePaint() for that.
@@ skipping 209 matching lines @@
   // The size of the delegated frame in DIP, set when SetDelegatedFrame was
   // called.
   gfx::Size delegated_frame_size_in_dip_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_