Add Mojo API for Blink hit testing

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 941c425b791fce38cbaa6912686c7d5423d372a6..abb9dcba7a8dacaf21846d89c8236f8d42f87020 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -898,11 +898,13 @@ void RenderWidgetHostViewAura::OnLegacyWindowDestroyed() {
 #endif
 
 void RenderWidgetHostViewAura::DidCreateNewRendererCompositorFrameSink(
-    viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink) {
+    viz::mojom::CompositorFrameSinkClient* renderer_compositor_frame_sink,
+    viz::mojom::TargetFrameForInputDelegate* input_delegate) {
   renderer_compositor_frame_sink_ = renderer_compositor_frame_sink;
+  target_frame_for_input_delegate_ = input_delegate;
   if (delegated_frame_host_) {
     delegated_frame_host_->DidCreateNewRendererCompositorFrameSink(
-        renderer_compositor_frame_sink_);
+        renderer_compositor_frame_sink_, input_delegate);
   }
 }
 
@@ -1951,9 +1953,9 @@ void RenderWidgetHostViewAura::CreateDelegatedFrameHostClient() {
   }
   delegated_frame_host_ = base::MakeUnique<DelegatedFrameHost>(
       frame_sink_id_, delegated_frame_host_client_.get());
-  if (renderer_compositor_frame_sink_) {
+  if (renderer_compositor_frame_sink_ && target_frame_for_input_delegate_) {
     delegated_frame_host_->DidCreateNewRendererCompositorFrameSink(
-        renderer_compositor_frame_sink_);
+        renderer_compositor_frame_sink_, target_frame_for_input_delegate_);
   }
   UpdateNeedsBeginFramesInternal();