compositor-worker: cc->blink mutation plumbing

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 4048e3b6ffddd6a697ba655bed0f423f2a982f92..f568c8d760eac686bebb330a0c7e794ca837d1e0 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -49,6 +49,7 @@
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
 #include "third_party/WebKit/public/platform/WebCompositeAndReadbackAsyncCallback.h"
+#include "third_party/WebKit/public/platform/WebCompositorMutations.h"
 #include "third_party/WebKit/public/platform/WebLayoutAndPaintAsyncCallback.h"
 #include "third_party/WebKit/public/platform/WebSize.h"
 #include "third_party/WebKit/public/web/WebKit.h"
@@ -911,6 +912,13 @@ void RenderWidgetCompositor::ApplyViewportDeltas(
       top_controls_delta);
 }
 
+void RenderWidgetCompositor::ApplyMutations(
+    const cc::LayerTreeMutations& mutations) {
+  TRACE_EVENT0("compositor-worker", "RenderWidgetCompositor::ApplyMutations");
+  widget_->webwidget()->applyMutations(
+      static_cast<const blink::WebCompositorMutations&>(mutations));
+}
+
 void RenderWidgetCompositor::RequestNewOutputSurface() {
   // If the host is closing, then no more compositing is possible.  This
   // prevents shutdown races between handling the close message and