Worked around infinite loop seen in Chrome on Windows when raising and...

plugin/win/main_win.cc

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 454 matching lines @@
   }
 
   // Limit the ways in which we can be reentrant.  Note that this WindowProc
   // may be called by different threads.  For example, IE will register plugin
   // instances on separate threads.
   o3d::Client::ScopedIncrement reentrance_count(obj->client());
 
   switch (Msg) {
     case WM_PAINT: {
       if (reentrance_count.get() > 1) {
+        // In Chrome, alert dialogs raised from JavaScript cause
+        // reentrant WM_PAINT messages to be dispatched and 100% CPU
+        // to be consumed unless we call this
+        ::ValidateRect(hWnd, NULL);
         break;  // Ignore this message; we're reentrant.
       }
       PAINTSTRUCT paint_struct;
       HDC hdc = ::BeginPaint(hWnd, &paint_struct);
       if (paint_struct.rcPaint.right - paint_struct.rcPaint.left != 0 ||
           paint_struct.rcPaint.bottom - paint_struct.rcPaint.top != 0) {
         if (obj->renderer()) {
           // It appears to be necessary to use GDI to paint something at least
           // once before D3D rendering will work in Vista with Aero.
           if (!obj->RecordPaint()) {
@@ skipping 490 matching lines @@
     StreamManager *stream_manager = obj->stream_manager();
 
     stream_manager->SetStreamFile(stream, fname);
   }
 
   int16 NPP_HandleEvent(NPP instance, void *event) {
     HANDLE_CRASHES;
     return 0;
   }
 }  // end extern "C"