WIP - compositor worker mega patch.

content/renderer/gpu/render_widget_compositor.h

Index: content/renderer/gpu/render_widget_compositor.h
diff --git a/content/renderer/gpu/render_widget_compositor.h b/content/renderer/gpu/render_widget_compositor.h
index 3a37e50d2e8dde020e8c32ac811a99b8345dee26..d9dabc0da1663ca940f2eacea13ba52ee008c726 100644
--- a/content/renderer/gpu/render_widget_compositor.h
+++ b/content/renderer/gpu/render_widget_compositor.h
@@ -39,6 +39,10 @@ class CompositorMessage;
 
 }
 
+namespace blink {
+class WebMutatorClient;
+}
+
 namespace content {
 class RenderWidget;
 
@@ -137,6 +141,8 @@ class CONTENT_EXPORT RenderWidgetCompositor
   void setShowDebugBorders(bool show) override;
   void setShowScrollBottleneckRects(bool show) override;
 
+  void setMutatorClient(blink::WebMutatorClient*) override;
+
   void updateTopControlsState(blink::WebTopControlsState constraints,
                               blink::WebTopControlsState current,
                               bool animate) override;
@@ -154,6 +160,8 @@ class CONTENT_EXPORT RenderWidgetCompositor
                            const gfx::Vector2dF& elastic_overscroll_delta,
                            float page_scale,
                            float top_controls_delta) override;
+  void ApplyMutations(
+      const cc::LayerTreeMutationMap& mutations) override;
   void RequestNewOutputSurface() override;
   void DidInitializeOutputSurface() override;
   void DidFailToInitializeOutputSurface() override;