Move WebMouseWheelEvent into its own header file.

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 10 matching lines @@
 #include "third_party/skia/include/core/SkImageInfo.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/surface/transport_dib.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace blink {
 class WebMouseEvent;
+class WebMouseWheelEvent;
 }
 
 namespace content {
 
 class RenderProcessHost;
 class RenderWidgetHostIterator;
 class RenderWidgetHostView;
 struct ScreenInfo;
 
 // A RenderWidgetHost manages the browser side of a browser<->renderer
@@ skipping 254 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_