Fix race condition with windowless plugin buffers. The problem, which is already fixed for Mac, is …

webkit/plugins/npapi/test/plugin_windowless_test.h

 // Copyright (c) 2011 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_PLUGINS_NPAPI_TEST_PLUGIN_EXECUTE_SCRIPT_DELETE_TEST_H_
 #define WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_EXECUTE_SCRIPT_DELETE_TEST_H_
 
 #include "webkit/plugins/npapi/test/plugin_test.h"
 
 namespace NPAPIClient {
@@ skipping 10 matching lines @@
 
   // NPAPI HandleEvent handler
   virtual NPError New(uint16 mode, int16 argc, const char* argn[],
                       const char* argv[], NPSavedData* saved) OVERRIDE;
   virtual int16 HandleEvent(void* event) OVERRIDE;
 
  protected:
   NPError ExecuteScript(NPNetscapeFuncs* browser, NPP id,
       const std::string& script, NPVariant* result);
   void ExecuteScriptDeleteInPaint(NPNetscapeFuncs* browser);
+  void ExecuteScriptResizeInPaint(NPNetscapeFuncs* browser);
   void MultipleInstanceSyncCalls(NPNetscapeFuncs* browser);
   void ConvertPoint(NPNetscapeFuncs* browser);
+
+  int paint_counter_;
 };
 
 }  // namespace NPAPIClient
 
 #endif  // WEBKIT_PLUGINS_NPAPI_TEST_PLUGIN_EXECUTE_SCRIPT_DELETE_TEST_H_