Track the cost of impl-side painting.

cc/picture_pile_impl.cc

Index: cc/picture_pile_impl.cc
===================================================================
--- cc/picture_pile_impl.cc	(revision 170195)
+++ cc/picture_pile_impl.cc	(working copy)
@@ -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 @@
   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 @@
     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