Make OffscreenCanvas animation in sync with its placeholder canvas's parent frame rate

third_party/WebKit/public/platform/WebLayerTreeView.h

Index: third_party/WebKit/public/platform/WebLayerTreeView.h
diff --git a/third_party/WebKit/public/platform/WebLayerTreeView.h b/third_party/WebKit/public/platform/WebLayerTreeView.h
index e2919800eed802e5f2de25b2d2fca72547a4750c..2867d422e21befb8d3916c8dcaaf55f551d8be9f 100644
--- a/third_party/WebKit/public/platform/WebLayerTreeView.h
+++ b/third_party/WebKit/public/platform/WebLayerTreeView.h
@@ -33,6 +33,7 @@
 #include "WebEventListenerProperties.h"
 #include "WebFloatPoint.h"
 #include "WebSize.h"
+#include "cc/surfaces/frame_sink_id.h"
 
 namespace cc {
 class AnimationHost;
@@ -183,6 +184,9 @@ class WebLayerTreeView {
 
   // Toggles scroll bottleneck rects on the HUD layer
   virtual void setShowScrollBottleneckRects(bool) {}
+
+  // Returns the FrameSinkId of the current render view
+  virtual cc::FrameSinkId getFrameSinkId() { return cc::FrameSinkId(); }
 };
 
 }  // namespace blink