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

views/widget/widget.h

 // Copyright (c) 2011 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 VIEWS_WIDGET_WIDGET_H_
 #define VIEWS_WIDGET_WIDGET_H_
 #pragma once
 
 #include <stack>
 
@@ skipping 487 matching lines @@
   }
   static ui::Compositor* (*compositor_factory())() {
     return compositor_factory_;
   }
 
   const ui::Compositor* GetCompositor() const;
   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
   // value changes. Pass true for |send_native_event| except for rare
   // cases where the view is a native control that's already sending a
   // native accessibility event and the duplicate event would cause
   // problems.
   void NotifyAccessibilityEvent(
       View* view,
       ui::AccessibilityTypes::Event event_type,
@@ skipping 212 matching lines @@
 
   // Tracks whether native widget has been initialized.
   bool native_widget_initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif // VIEWS_WIDGET_WIDGET_H_