Remove ALL usage of CriticalSectionWrapper.

webrtc/system_wrappers/source/rw_lock.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/system_wrappers/include/rw_lock_wrapper.h"
 
 #include <assert.h>
 
 #if defined(_WIN32)
 #include "webrtc/system_wrappers/source/rw_lock_win.h"
-#include "webrtc/system_wrappers/source/rw_lock_winxp_win.h"
 #else
 #include "webrtc/system_wrappers/source/rw_lock_posix.h"
 #endif
 
 namespace webrtc {
 
 RWLockWrapper* RWLockWrapper::CreateRWLock() {
 #ifdef _WIN32
-  // Native implementation is faster, so use that if available.
-  RWLockWrapper* lock = RWLockWin::Create();
-  if (lock) {
-    return lock;
-  }
-  return new RWLockWinXP();
+  return RWLockWin::Create();
 #else
   return RWLockPosix::Create();
 #endif
 }
 
 }  // namespace webrtc