Added ability to dynamically toggle frame throttling in the scheduler.

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index e60f96eb423a23eedb726311378c1b29ac99c919..ade5172486376ec6e9f53dac7870b436936b5d5d 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -242,6 +242,8 @@ class CC_EXPORT LayerTreeHost {
   void SetVisible(bool visible);
   bool visible() const { return visible_; }
 
+  void SetThrottleFrameProduction(bool throttle);
+
   void StartPageScaleAnimation(const gfx::Vector2d& target_offset,
                                bool use_anchor,
                                float scale,
@@ -484,6 +486,8 @@ class CC_EXPORT LayerTreeHost {
   uint32_t surface_id_namespace_;
   uint32_t next_surface_sequence_;
 
+  int swap_interval_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };