Implements core logic for Pixel Canvas

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 <stddef.h>
 
 #include <memory>
@@ skipping 406 matching lines @@
   const gfx::Size& frame_size_in_dip_for_testing() const {
     return frame_size_in_dip_;
   }
 
   // Force use of and cache render surface. Note that this also disables
   // occlusion culling in favor of efficient caching. This should
   // only be used when paying the cost of creating a render
   // surface even if layer is invisible is not a problem.
   void SetCacheRenderSurface(bool cache_render_surface);
 
+  // The back link from the mask layer to it's associated masked layer.
+  // We keep this reference for the case that if the mask layer gets deleted
+  // while attached to the main layer before the main layer is deleted.
+  const Layer* layer_mask_back_link() const { return layer_mask_back_link_; }
+
  private:
   friend class LayerOwner;
   class LayerMirror;
 
   void CollectAnimators(std::vector<scoped_refptr<LayerAnimator> >* animators);
 
   // Stacks |child| above or below |other|.  Helper method for StackAbove() and
   // StackBelow().
   void StackRelativeTo(Layer* child, Layer* other, bool above);
 
@@ skipping 151 matching lines @@
   // The size of the frame or texture in DIP, set when SetShowDelegatedContent
   // or SetTextureMailbox was called.
   gfx::Size frame_size_in_dip_;
 
   DISALLOW_COPY_AND_ASSIGN(Layer);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_H_