[cc] Track the rendering & painting cost of impl-side painting.

cc/picture_pile_impl.cc

Index: cc/picture_pile_impl.cc
diff --git a/cc/picture_pile_impl.cc b/cc/picture_pile_impl.cc
index 217a5eb4ee4e2922bbf9b85f77cbbfe791c91e4c..2f898281360bd2040aa0751840ebe096a5001ade 100644
--- a/cc/picture_pile_impl.cc
+++ b/cc/picture_pile_impl.cc
@@ -4,7 +4,9 @@
 
 #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"
 
 namespace cc {
 
@@ -28,7 +30,10 @@ scoped_refptr<PicturePileImpl> PicturePileImpl::CloneForDrawing() const {
   return clone;
 }
 
-void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect) {
+void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect,
+                             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());
@@ -39,8 +44,14 @@ void PicturePileImpl::Raster(SkCanvas* canvas, gfx::Rect rect) {
     if (!pile_[i]->LayerRect().Intersects(rect))
       continue;
     pile_[i]->Raster(canvas);
+
+    SkISize deviceSize = canvas->getDeviceSize();
+    stats->totalPixelsRasterized += deviceSize.width() * deviceSize.height();
   }
   canvas->restore();
+
+  stats->totalRasterizeTimeInSeconds += (base::TimeTicks::Now() -
+                                         rasterizeBeginTime).InSecondsF();
 }
 
 }  // namespace cc