Rework View Layer Draw() to use the Layer::DrawTree() method and the LayerDelegate.

views/widget/widget.h

Index: views/widget/widget.h
===================================================================
--- views/widget/widget.h	(revision 100773)
+++ views/widget/widget.h	(working copy)
@@ -504,8 +504,8 @@
   ui::Compositor* GetCompositor();
 
   // Invokes method of same name on the NativeWidget.
-  void MarkLayerDirty();
-  void CalculateOffsetToAncestorWithLayer(gfx::Point* offset, View** ancestor);
+  void CalculateOffsetToAncestorWithLayer(gfx::Point* offset,
+                                          ui::Layer** layer_parent);
 
   // Notifies assistive technology that an accessibility event has
   // occurred on |view|, such as when the view is focused or when its