Add cheapness predictor success histogram

cc/tile_manager.h

Index: cc/tile_manager.h
diff --git a/cc/tile_manager.h b/cc/tile_manager.h
index a8490b6facdb4482d032862fe3b0712c43135109..0b47a822c5cbbbcb2c92ca8492dec44e148665bd 100644
--- a/cc/tile_manager.h
+++ b/cc/tile_manager.h
@@ -165,11 +165,17 @@ class CC_EXPORT TileManager {
   static void RunRasterTask(uint8* buffer,
                             const gfx::Rect& rect,
                             float contents_scale,
+                            bool use_cheapness_estimator,
                             PicturePileImpl* picture_pile,
                             RenderingStats* stats);
   static void RunImageDecodeTask(skia::LazyPixelRef* pixel_ref,
                                  RenderingStats* stats);
 
+  static void RecordCheapnessPredictorCorrectness(

[nduca, 2013/02/05 00:22:26]

indentation, follow chrome style guide

foo(bar,
    baz)

or
  foo(
      bar, baz)

In this case, probably the frist

+    bool is_predicted_cheap,
+    bool is_actually_cheap
+  );
+
   TileManagerClient* client_;
   scoped_ptr<ResourcePool> resource_pool_;
   scoped_ptr<RasterWorkerPool> raster_worker_pool_;