Ensure Windows window classes are unregistered on shutdown (take 2)

base/message_pump_win.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 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.
 
 #include "base/message_pump_win.h"
 
 #include <math.h>
 
 #include "base/histogram.h"
 #include "base/win_util.h"
 
@@ skipping 69 matching lines @@
 
 //-----------------------------------------------------------------------------
 // MessagePumpForUI public:
 
 MessagePumpForUI::MessagePumpForUI() {
   InitMessageWnd();
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
   DestroyWindow(message_hwnd_);
+  UnregisterClass(kWndClass, GetModuleHandle(NULL));
 }
 
 void MessagePumpForUI::ScheduleWork() {
   if (InterlockedExchange(&have_work_, 1))
     return;  // Someone else continued the pumping.
 
   // Make sure the MessagePump does some work for us.
   PostMessage(message_hwnd_, kMsgHaveWork, reinterpret_cast<WPARAM>(this), 0);
 }
 
@@ skipping 446 matching lines @@
     if (!filter || it->handler == filter) {
       *item = *it;
       completed_io_.erase(it);
       return true;
     }
   }
   return false;
 }
 
 }  // namespace base