Implements core logic for Pixel Canvas

ui/compositor/layer.h

Index: ui/compositor/layer.h
diff --git a/ui/compositor/layer.h b/ui/compositor/layer.h
index 7c1ab4bf4a42e5755ee6031de1bcd3451a29dbb0..b7ba24d4e34952ab328675ec1a146a173f90601f 100644
--- a/ui/compositor/layer.h
+++ b/ui/compositor/layer.h
@@ -415,6 +415,8 @@ class COMPOSITOR_EXPORT Layer
     return frame_size_in_dip_;
   }
 
+  const Layer* layer_mask_back_link() const { return layer_mask_back_link_; }

[danakj, 2017/07/26 16:06:04]

can you add a comment explaining what this is?

[malaykeshav, 2017/07/26 18:34:45]

Done. I am not why we need to duplicate the comment for |layer_mask_back_link_|
at the getter as well as the member variable declaration.

+
  private:
   friend class LayerOwner;
   class LayerMirror;