Allow CanvasSkia to bind to an existing SkCanvas.

ui/gfx/compositor/layer.cc

 // 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.
 
 #include "ui/gfx/compositor/layer.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 260 matching lines @@
   gfx::Rect draw_rect = texture_.get() ? invalid_rect_.Intersect(local_bounds) :
       local_bounds;
   if (draw_rect.IsEmpty()) {
     invalid_rect_ = gfx::Rect();
     return;
   }
   scoped_ptr<gfx::Canvas> canvas(gfx::Canvas::CreateCanvas(
       draw_rect.width(), draw_rect.height(), false));
   canvas->TranslateInt(-draw_rect.x(), -draw_rect.y());
   delegate_->OnPaintLayer(canvas.get());
-  SetCanvas(*canvas->AsCanvasSkia(), draw_rect.origin());
+  SetCanvas(*canvas->GetSkCanvas(), draw_rect.origin());
 }
 
 void Layer::RecomputeHole() {
   if (type_ == LAYER_HAS_NO_TEXTURE)
     return;
 
   // Reset to default.
   hole_rect_ = gfx::Rect();
 
   // 1) We cannot do any hole punching if any child has a transform.
@@ skipping 186 matching lines @@
 
 void Layer::SetTransformFromAnimator(const Transform& transform) {
   SetTransformImmediately(transform);
 }
 
 void Layer::SetOpacityFromAnimator(float opacity) {
   SetOpacityImmediately(opacity);
 }
 
 }  // namespace ui