Allow MainThreadEventQueue to call the RenderWidget directly.

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 78d5b3fa9966c00e617d91f79135240f91379f46..5711ed54896d5b717f722d56302dab5283fc77ff 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -101,6 +101,7 @@ class CompositorDependencies;
 class ExternalPopupMenu;
 class FrameSwapMessageQueue;
 class ImeEventGuard;
+class MainThreadEventQueue;
 class PepperPluginInstanceImpl;
 class RenderFrameImpl;
 class RenderFrameProxy;
@@ -264,9 +265,6 @@ class CONTENT_EXPORT RenderWidget
   void OnDidHandleKeyEvent() override;
   void OnDidOverscroll(const ui::DidOverscrollParams& params) override;
   void OnInputEventAck(std::unique_ptr<InputEventAck> input_event_ack) override;
-  void NotifyInputEventHandled(blink::WebInputEvent::Type handled_type,
-                               blink::WebInputEventResult result,
-                               InputEventAckState ack_result) override;
   void SetInputHandler(RenderWidgetInputHandler* input_handler) override;
   void ShowVirtualKeyboard() override;
   void UpdateTextInputState() override;
@@ -416,6 +414,11 @@ class CONTENT_EXPORT RenderWidget
   uint32_t GetContentSourceId();
   void IncrementContentSourceId();
 
+  virtual InputEventAckState HandleInputEvent(
+      const blink::WebCoalescedInputEvent& input_event,
+      const ui::LatencyInfo& latency_info,
+      InputEventDispatchType dispatch_type);
+
  protected:
   // Friend RefCounted so that the dtor can be non-public. Using this class
   // without ref-counting is an error.
@@ -868,6 +871,8 @@ class CONTENT_EXPORT RenderWidget
   // to replace it. See https://crbug.com/695579.
   uint32_t current_content_source_id_;
 
+  scoped_refptr<MainThreadEventQueue> input_event_queue_;
+
   base::WeakPtrFactory<RenderWidget> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);