Allow ui::Compositor to disable commits during tab-switch

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index 47d4cd0d7e30866f980299191cd5994d386673b9..600308d9c698ea896e32e5b4e0bf8e8996374246 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -269,6 +269,7 @@ class COMPOSITOR_EXPORT Compositor
   void DidPostSwapBuffers() override;
   void DidAbortSwapBuffers() override;
 
+  void SetDeferCommits(bool defer_commits);
   bool IsLocked() { return compositor_lock_ != NULL; }
 
   const cc::LayerTreeDebugState& GetLayerTreeDebugState() const;
@@ -319,8 +320,6 @@ class COMPOSITOR_EXPORT Compositor
   int last_started_frame_;
   int last_ended_frame_;
 
-  bool disable_schedule_composite_;
-
   CompositorLock* compositor_lock_;
 
   LayerAnimatorCollection layer_animator_collection_;