Reland of Delay Input.dispatchKeyEvent response until after key event ack.

content/public/browser/render_widget_host.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_
 
 #include <stdint.h>
 
 #include "base/callback.h"
@@ skipping 225 matching lines @@
   virtual void AddKeyPressEventCallback(
       const KeyPressEventCallback& callback) = 0;
   virtual void RemoveKeyPressEventCallback(
       const KeyPressEventCallback& callback) = 0;
 
   // Add/remove a callback that can handle all kinds of mouse events.
   typedef base::Callback<bool(const blink::WebMouseEvent&)> MouseEventCallback;
   virtual void AddMouseEventCallback(const MouseEventCallback& callback) = 0;
   virtual void RemoveMouseEventCallback(const MouseEventCallback& callback) = 0;
 
-  // Observer for WebInputEvents (but not input event acks).
+  // Observer for WebInputEvents.
   class InputEventObserver {
    public:
     virtual ~InputEventObserver() {}
 
-    virtual void OnInputEvent(const blink::WebInputEvent&) = 0;
+    virtual void OnInputEvent(const blink::WebInputEvent&) {};
+    virtual void OnInputEventAck(const blink::WebInputEvent&) {};
   };
 
   // Add/remove an input event observer.
   virtual void AddInputEventObserver(InputEventObserver* observer) = 0;
   virtual void RemoveInputEventObserver(InputEventObserver* observer) = 0;
 
   // Get the screen info corresponding to this render widget.
   virtual void GetScreenInfo(ScreenInfo* result) = 0;
 
   // Sends a compositor proto to the render widget.
@@ skipping 33 matching lines @@
   // This allows the renderer to reset some state.
   virtual void DragSourceSystemDragEnded() {};
 
   // Filters drop data before it is passed to RenderWidgetHost.
   virtual void FilterDropData(DropData* drop_data) {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_