Add fixed raster scale use counter histograms.

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 8f72d022da2a983415e26a6b2c946e1314d55470..709c1a6c920eaeb3cdeb2d6744c3c64a07cfd8e8 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -531,6 +531,13 @@ class CC_EXPORT LayerImpl {
 
   void ClearLinksToOtherLayers();
 
+  void set_has_will_change_transform_hint(bool has_will_change) {
+    has_will_change_transform_hint_ = has_will_change;
+  }
+  bool has_will_change_transform_hint() const {
+    return has_will_change_transform_hint_;
+  }
+
  protected:
   LayerImpl(LayerTreeImpl* layer_impl,
             int id,
@@ -670,6 +677,8 @@ class CC_EXPORT LayerImpl {
   // If true, the layer or one of its descendants has a touch handler.
   bool layer_or_descendant_has_touch_handler_;
 
+  bool has_will_change_transform_hint_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };