toggle FPS counter in compositor

cc/layer_tree_host_impl.h

Index: cc/layer_tree_host_impl.h
diff --git a/cc/layer_tree_host_impl.h b/cc/layer_tree_host_impl.h
index be31eb90eafda3765acfee4c8c985efec29f2bff..7827f64abc25c4ee28a1f1500c5af1214e1b88e3 100644
--- a/cc/layer_tree_host_impl.h
+++ b/cc/layer_tree_host_impl.h
@@ -261,6 +261,9 @@ public:
     template<typename RenderPassCuller>
     static void removeRenderPasses(RenderPassCuller, FrameData&);
 
+    void setShowFPSCounter(bool show);
+    bool showFPSCounter() const;
+
 protected:
     CCLayerTreeHostImpl(const CCLayerTreeSettings&, CCLayerTreeHostImplClient*);
 
@@ -325,6 +328,8 @@ private:
     SkColor m_backgroundColor;
     bool m_hasTransparentBackground;
 
+    bool m_showFPSCounter;
+
     // If this is true, it is necessary to traverse the layer tree ticking the animators.
     bool m_needsAnimateLayers;
     bool m_pinchGestureActive;