Add Mojo API for Blink hit testing

content/browser/renderer_host/render_widget_host_view_aura.h

Index: content/browser/renderer_host/render_widget_host_view_aura.h
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 49674e53ff1c90f63d5039c073d24d64f652bcdf..b1419ea1be612e476bbd7c22f5e35c710d95c9e3 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -169,8 +169,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
   bool LockMouse() override;
   void UnlockMouse() override;
   void DidCreateNewRendererCompositorFrameSink(
-      viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink)
-      override;
+      viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink,
+      viz::mojom::TargetFrameForInputDelegate*) override;
   void SubmitCompositorFrame(const viz::LocalSurfaceId& local_surface_id,
                              cc::CompositorFrame frame) override;
   void OnDidNotProduceFrame(const viz::BeginFrameAck& ack) override;
@@ -602,6 +602,8 @@ class CONTENT_EXPORT RenderWidgetHostViewAura
 
   viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink_ =
       nullptr;
+  viz::mojom::TargetFrameForInputDelegate* target_frame_for_input_delegate_ =
+      nullptr;
 
   // While this is a ui::EventHandler for targetting, |event_handler_| actually
   // provides an implementation, and directs events to |host_|.