Add Mojo API for Blink hit testing

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index c33ffd978b53d042bd25bd412dd622667d1cb4a3..7a4dcead12c2e6cf529713c1ae0cd8642b7e02a1 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -569,7 +569,8 @@ class CONTENT_EXPORT RenderWidgetHostImpl
 
   void RequestCompositorFrameSink(
       viz::mojom::CompositorFrameSinkRequest request,
-      viz::mojom::CompositorFrameSinkClientPtr client);
+      viz::mojom::CompositorFrameSinkClientPtr client,
+      viz::mojom::TargetFrameForInputDelegatePtr hit_test);
 
   const cc::CompositorFrameMetadata& last_frame_metadata() {
     return last_frame_metadata_;
@@ -977,6 +978,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl
 
   mojo::Binding<viz::mojom::CompositorFrameSink> compositor_frame_sink_binding_;
   viz::mojom::CompositorFrameSinkClientPtr renderer_compositor_frame_sink_;
+  viz::mojom::TargetFrameForInputDelegatePtr target_frame_for_input_delegate_;
 
   cc::CompositorFrameMetadata last_frame_metadata_;