Adding hooks for gathering total pixels painted and rasterized stats.

cc/bitmap_content_layer_updater.cc

Index: cc/bitmap_content_layer_updater.cc
diff --git a/cc/bitmap_content_layer_updater.cc b/cc/bitmap_content_layer_updater.cc
index 66828ff772fad1d0ba5450020dcf0238e16d97a3..7c47bae9712a973e4fbab1c98e908026ba00c61f 100644
--- a/cc/bitmap_content_layer_updater.cc
+++ b/cc/bitmap_content_layer_updater.cc
@@ -7,6 +7,7 @@
 #include "cc/bitmap_content_layer_updater.h"
 
 #include "cc/layer_painter.h"
+#include "cc/rendering_stats.h"
 #include "cc/resource_update.h"
 #include "cc/resource_update_queue.h"
 #include "skia/ext/platform_canvas.h"
@@ -55,6 +56,8 @@ void BitmapContentLayerUpdater::prepareToUpdate(const IntRect& contentRect, cons
         m_canvas = make_scoped_ptr(skia::CreateBitmapCanvas(m_canvasSize.width(), m_canvasSize.height(), m_opaque));
     }
 
+    stats.totalPixelsRasterized += contentRect.width() * contentRect.height();
+
     paintContents(m_canvas.get(), contentRect, contentsWidthScale, contentsHeightScale, resultingOpaqueRect, stats);
 }