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

views/layer_helper.h

Index: views/layer_helper.h
===================================================================
--- views/layer_helper.h	(revision 100773)
+++ views/layer_helper.h	(working copy)
@@ -42,14 +42,6 @@
   }
   const gfx::Rect& clip_rect() const { return clip_rect_; }
 
-  // If true, the layer's bitmap is out of date and needs to be updated.
-  void set_bitmap_needs_updating(bool value) {
-    bitmap_needs_updating_ = value;
-  }
-  bool bitmap_needs_updating() const {
-    return bitmap_needs_updating_;
-  }
-
   // If true the layer was explicitly turned on.
   void set_paint_to_layer(bool value) { paint_to_layer_ = value; }
   bool paint_to_layer() const { return paint_to_layer_; }
@@ -100,9 +92,6 @@
   // TODO(sky): this should be passed into paint.
   gfx::Rect clip_rect_;
 
-  // Is the layers bitmap out of date?
-  bool bitmap_needs_updating_;
-
   bool fills_bounds_opaquely_;
 
   // If true the bitmap is always up to date.