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

views/view.h

Index: views/view.h
===================================================================
--- views/view.h	(revision 100773)
+++ views/view.h	(working copy)
@@ -17,6 +17,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
 #include "ui/base/dragdrop/os_exchange_data.h"
+#include "ui/gfx/compositor/layer_delegate.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/rect.h"
 #include "views/accelerator.h"
@@ -91,7 +92,8 @@
 //   accessed from the main thread.
 //
 /////////////////////////////////////////////////////////////////////////////
-class VIEWS_EXPORT View : public AcceleratorTarget {
+class VIEWS_EXPORT View : public ui::LayerDelegate,
+                          public AcceleratorTarget {
  public:
   typedef std::vector<View*> Views;
 
@@ -967,23 +969,6 @@
   // SchedulePaintInRect instead.
   virtual void SchedulePaintInternal(const gfx::Rect& r);
 
-  // If our layer is out of date invokes Paint() with a canvas that is then
-  // copied to the layer. If the layer is not out of date recursively descends
-  // in case any children needed their layers updated.
-  //
-  // This is invoked internally by Widget and painting code.
-  virtual void PaintToLayer(const gfx::Rect& dirty_rect);
-
-  // Instructs the compositor to show our layer and all children layers.
-  // Invokes OnWillCompositeLayer() for any views that have layers.
-  //
-  // This is invoked internally by Widget and painting code.
-  virtual void PaintComposite();
-
-  // Invoked from |PaintComposite| if this view has a layer and before the
-  // layer is rendered by the compositor.
-  virtual void OnWillCompositeLayer();
-
   // This creates a layer for the view, if one does not exist. It then
   // passes the texture to a layer associated with the view. While an external
   // texture is set, the view will not update the layer contents.
@@ -1000,10 +985,11 @@
   // Marks the layer this view draws into as dirty.
   virtual void MarkLayerDirty();
 
-  // Returns the offset from this view to the neareset ancestor with a layer.
-  // If |ancestor| is non-NULL it is set to the nearset ancestor with a layer.
-  virtual void CalculateOffsetToAncestorWithLayer(gfx::Point* offset,
-                                                  View** ancestor);
+  // Returns the offset from this view to the nearest ancestor with a layer.
+  // If |ancestor| is non-NULL it is set to the nearest ancestor with a layer.
+  virtual void CalculateOffsetToAncestorWithLayer(
+      gfx::Point* offset,
+      ui::Layer** layer_parent);
 
   // Creates a layer for this and recurses through all descendants.
   virtual void CreateLayerIfNecessary();
@@ -1024,6 +1010,9 @@
   // descendants.
   virtual void UpdateLayerBounds(const gfx::Point& offset);
 
+  // Overridden from ui::LayerDelegate:
+  virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE;
+
   // Input ---------------------------------------------------------------------
 
   // Called by HitTest to see if this View has a custom hit test mask. If the
@@ -1139,6 +1128,10 @@
   // new bounds.
   void SchedulePaintBoundsChanged(SchedulePaintType type);
 
+  // Common Paint() code shared by accelerated and non-accelerated code paths to
+  // invoke OnPaint() on the View.
+  void PaintCommon(gfx::Canvas* canvas);
+
   // Tree operations -----------------------------------------------------------
 
   // Removes |view| from the hierarchy tree.  If |update_focus_cycle| is true,