cc: Apply contents scales to impl-side painting rasterization

cc/picture_pile_impl.cc

 // Copyright 2012 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 "base/debug/trace_event.h"
 #include "cc/picture_pile_impl.h"
 #include "cc/rendering_stats.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSize.h"
 
@@ skipping 12 matching lines @@
 scoped_refptr<PicturePileImpl> PicturePileImpl::CloneForDrawing() const {
   TRACE_EVENT0("cc", "PicturePileImpl::CloneForDrawing");
   scoped_refptr<PicturePileImpl> clone = Create();
   for (PicturePile::Pile::const_iterator i = pile_.begin();
        i != pile_.end(); ++i)
     clone->pile_.push_back((*i)->Clone());
 
   return clone;
 }
 
-void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect,
-                             RenderingStats* stats) {
+void PicturePileImpl::Raster(
+    SkCanvas* canvas,
+    gfx::Rect rect,
+    float contents_scale,
+    RenderingStats* stats) {
   base::TimeTicks rasterizeBeginTime = base::TimeTicks::Now();
 
   // TODO(enne): do this more efficiently, i.e. top down with Skia clips
   canvas->save();
   canvas->translate(-rect.x(), -rect.y());
   SkRect layer_skrect = SkRect::MakeXYWH(rect.x(), rect.y(),
                                          rect.width(), rect.height());
   canvas->clipRect(layer_skrect);
+  canvas->scale(contents_scale, contents_scale);
   for (PicturePile::Pile::const_iterator i = pile_.begin();
        i != pile_.end(); ++i) {
     if (!(*i)->LayerRect().Intersects(rect))
       continue;
     (*i)->Raster(canvas);
 
     SkISize deviceSize = canvas->getDeviceSize();
     stats->totalPixelsRasterized += deviceSize.width() * deviceSize.height();
   }
   canvas->restore();
 
   stats->totalRasterizeTimeInSeconds += (base::TimeTicks::Now() -
                                          rasterizeBeginTime).InSecondsF();
 }
 
 }  // namespace cc