Fix Silverlight windowless plugin painting issues. This fixes the following...

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 287 matching lines @@
   std::vector<ClientInfo> clients_;
 
   bool windowless_;
   HWND window_;
   WebCore::Element* element_;
   WebFrameImpl* webframe_;
 
   WebPluginDelegate* delegate_;
   bool force_geometry_update_;
   bool visible_;
-  // Set when we receive the first paint notification for the plugin widget.
+  // Set when we receive the first paint notification for a windowed
+  // plugin widget.
   bool received_first_paint_notification_;
 
   WebPluginContainer* widget_;
 
   typedef std::map<WebPluginResourceClient*, MultipartResponseDelegate*>
       MultiPartResponseHandlerMap;
   // Tracks HTTP multipart response handlers instantiated for
   // a WebPluginResourceClient instance.
   MultiPartResponseHandlerMap multi_part_response_map_;
 
   // The plugin source URL.
   GURL plugin_url_;
 
   // 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_