Add Mojo API for Blink hit testing

content/browser/renderer_host/delegated_frame_host.h

Index: content/browser/renderer_host/delegated_frame_host.h
diff --git a/content/browser/renderer_host/delegated_frame_host.h b/content/browser/renderer_host/delegated_frame_host.h
index 97bfb3661f11a15cc5b25ec51179aebe51cb0599..8335fe13ab53a0e077c6253fccf0cd39a74af847 100644
--- a/content/browser/renderer_host/delegated_frame_host.h
+++ b/content/browser/renderer_host/delegated_frame_host.h
@@ -118,7 +118,8 @@ class CONTENT_EXPORT DelegatedFrameHost
   // Public interface exposed to RenderWidgetHostView.
 
   void DidCreateNewRendererCompositorFrameSink(
-      viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink);
+      viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink,
+      viz::mojom::FrameInputHitTest*);
   void SubmitCompositorFrame(const viz::LocalSurfaceId& local_surface_id,
                              cc::CompositorFrame frame);
   void ClearDelegatedFrame();
@@ -245,7 +246,8 @@ class CONTENT_EXPORT DelegatedFrameHost
   // initiate a copy-into-video-frame request.
   void AttemptFrameSubscriberCapture(const gfx::Rect& damage_rect);
 
-  void CreateCompositorFrameSinkSupport();
+  void CreateCompositorFrameSinkSupport(
+      viz::mojom::FrameInputHitTest* = nullptr);
   void ResetCompositorFrameSinkSupport();
 
   const viz::FrameSinkId frame_sink_id_;