WIP - compositor worker mega patch.

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 441c36f553fb3eda68a11589bd80694d71add796..9a89bd48723680c969dbfc3032efe6d5b6e4915c 100644
--- a/third_party/WebKit/public/platform/WebLayerTreeView.h
+++ b/third_party/WebKit/public/platform/WebLayerTreeView.h
@@ -40,6 +40,7 @@ namespace blink {
 
 class WebCompositeAndReadbackAsyncCallback;
 class WebCompositorAnimationTimeline;
+class WebCompositorMutatorClient;
 class WebLayer;
 class WebLayoutAndPaintAsyncCallback;
 struct WebPoint;
@@ -156,6 +157,9 @@ public:
 
     // Toggles scroll bottleneck rects on the HUD layer
     virtual void setShowScrollBottleneckRects(bool) { }
+
+    // Mutations are plumbed back to the layer tree via the mutator client.
+    virtual void setMutatorClient(WebCompositorMutatorClient*) { }
 };
 
 } // namespace blink