Add the "virtual" keyword on method overrides that are missing it.

webkit/glue/plugins/pepper_widget.h

 // Copyright (c) 2010 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 WEBKIT_GLUE_PLUGINS_PEPPER_WIDGET_H_
 #define WEBKIT_GLUE_PLUGINS_PEPPER_WIDGET_H_
 
 #include "base/scoped_ptr.h"
 #include "ppapi/c/pp_rect.h"
 #include "webkit/glue/plugins/pepper_resource.h"
 
 struct PPB_Widget_Dev;
 struct PP_InputEvent;
 
 namespace pepper {
 
 class ImageData;
 class PluginInstance;
 
 class Widget : public Resource  {
  public:
   explicit Widget(PluginInstance* instance);
   virtual ~Widget();
 
   // Returns a pointer to the interface implementing PPB_Widget that is
   // exposed to the plugin.
   static const PPB_Widget_Dev* GetInterface();
 
   // Resource overrides.
-  Widget* AsWidget() { return this; }
+  virtual Widget* AsWidget();
 
   // PPB_Widget implementation.
   virtual bool Paint(const PP_Rect* rect, ImageData* image) = 0;
   virtual bool HandleEvent(const PP_InputEvent* event) = 0;
   bool GetLocation(PP_Rect* location);
   void SetLocation(const PP_Rect* location);
 
   // Notifies the plugin instance that the given rect needs to be repainted.
   void Invalidate(const PP_Rect* dirty);
   PluginInstance* instance() { return instance_; }
 
  protected:
   virtual void SetLocationInternal(const PP_Rect* location) = 0;
   PP_Rect location() const { return location_; }
 
  private:
   scoped_refptr<PluginInstance> instance_;
   PP_Rect location_;
 };
 
 }  // namespace pepper
 
 #endif  // WEBKIT_GLUE_PLUGINS_PEPPER_WIDGET_H_