WIP - compositor worker mega patch.

cc/blink/web_compositor_support_impl.h

Index: cc/blink/web_compositor_support_impl.h
diff --git a/cc/blink/web_compositor_support_impl.h b/cc/blink/web_compositor_support_impl.h
index d32d0e1800306c71f7286a579cb5d1be4a042e18..d9853f4e1237091a616a05dd8ff6ba34e1339886 100644
--- a/cc/blink/web_compositor_support_impl.h
+++ b/cc/blink/web_compositor_support_impl.h
@@ -16,6 +16,8 @@
 
 namespace blink {
 class WebGraphicsContext3D;
+class WebMutator;
+class WebMutatorClient;
 }
 
 namespace cc_blink {
@@ -57,6 +59,8 @@ class CC_BLINK_EXPORT WebCompositorSupportImpl
   blink::WebTransformAnimationCurve* createTransformAnimationCurve() override;
   blink::WebTransformOperations* createTransformOperations() override;
   blink::WebFilterOperations* createFilterOperations() override;
+  blink::WebMutatorClient* createMutatorClient(
+      blink::WebMutator* mutator) override;
 
   blink::WebCompositorAnimationPlayer* createAnimationPlayer() override;
   blink::WebCompositorAnimationTimeline* createAnimationTimeline() override;