This fixes bug http://code.google.com/p/chromium/issues/detail?id=3881, which...

webkit/glue/webplugin_impl.h

 // Copyright (c) 2006-2008 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_WEBPLUGIN_IMPL_H_
 #define WEBKIT_GLUE_WEBPLUGIN_IMPL_H_
 
 #include <string>
 #include <map>
 #include <vector>
@@ skipping 46 matching lines @@
   NPObject* GetPluginScriptableObject();
   
   // Widget methods:
   virtual void setFrameRect(const WebCore::IntRect& rect);
   virtual void paint(WebCore::GraphicsContext*, const WebCore::IntRect& rect);
   virtual void invalidateRect(const WebCore::IntRect&);
   virtual void setFocus();
   virtual void show();
   virtual void hide();
   virtual void handleEvent(WebCore::Event* event);
-  virtual void frameRectsChanged() const {}
+  virtual void frameRectsChanged() const;
+  virtual void setParentVisible(bool visible);
 
 #if USE(JSC)
   virtual bool isPluginView() const;
 #endif
 
   // Returns window-relative rectangles that should clip this widget.
   // Only rects that intersect the given bounds are relevant.
   // Use this to implement iframe shim behavior.
   //
   // TODO(tulrich): add this method to WebCore/platform/Widget.h so it
@@ skipping 105 matching lines @@
 
   void ShowModalHTMLDialog(const GURL& url, int width, int height,
                            const std::string& json_arguments,
                            std::string* json_retval);
   void OnMissingPluginStatus(int status);
   void Invalidate();
   void InvalidateRect(const gfx::Rect& rect);
 
   // Widget implementation:
   virtual WebCore::IntRect windowClipRect() const;
-  virtual void geometryChanged() const;
 
   // Returns window-relative rectangles that should clip this widget.
   // Only rects that intersect the given bounds are relevant.
   // Use this to implement iframe shim behavior.
   //
   // TODO(tulrich): windowCutoutRects() is not in WebCore::Widgets
   // yet; need to add it.
   void windowCutoutRects(const WebCore::IntRect& bounds,
                          WTF::Vector<WebCore::IntRect>* rects) const;
 
@@ skipping 118 matching lines @@
   // Indicates if the download would be initiated by the plugin or us.
   bool load_manually_;
 
   // Indicates if this is the first geometry update received by the plugin.
   bool first_geometry_update_;
 
   DISALLOW_COPY_AND_ASSIGN(WebPluginImpl);
 };
 
 #endif  // #ifndef WEBKIT_GLUE_WEBPLUGIN_IMPL_H_