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..2385f4c5345b9ebab0adb63c2674d53fd578ab07 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -41,6 +41,7 @@
 #include "content/common/drag_event_source_info.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/common/input/input_handler.mojom.h"
+#include "content/common/input/input_hit_test.mojom.h"
 #include "content/common/input/synthetic_gesture_packet.h"
 #include "content/common/render_widget_surface_properties.h"
 #include "content/common/view_message_enums.h"
@@ -569,7 +570,8 @@ class CONTENT_EXPORT RenderWidgetHostImpl
 
   void RequestCompositorFrameSink(
       viz::mojom::CompositorFrameSinkRequest request,
-      viz::mojom::CompositorFrameSinkClientPtr client);
+      viz::mojom::CompositorFrameSinkClientPtr client,
+      viz::mojom::FrameInputHitTestPtr hit_test);
 
   const cc::CompositorFrameMetadata& last_frame_metadata() {
     return last_frame_metadata_;
@@ -977,6 +979,7 @@ class CONTENT_EXPORT RenderWidgetHostImpl
 
   mojo::Binding<viz::mojom::CompositorFrameSink> compositor_frame_sink_binding_;
   viz::mojom::CompositorFrameSinkClientPtr renderer_compositor_frame_sink_;
+  viz::mojom::FrameInputHitTestPtr frame_hit_test_;
 
   cc::CompositorFrameMetadata last_frame_metadata_;