Revert of "Create rtc::AtomicInt POD struct."

webrtc/base/criticalsection.h

 /*
  *  Copyright 2004 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.
  */
 
@@ skipping 88 matching lines @@
 };
 
 // A POD lock used to protect global variables. Do NOT use for other purposes.
 // No custom constructor or private data member should be added.
 class LOCKABLE GlobalLockPod {
  public:
   void Lock() EXCLUSIVE_LOCK_FUNCTION();
 
   void Unlock() UNLOCK_FUNCTION();
 
-  AtomicInt lock_acquired;
+  volatile int lock_acquired;
 };
 
 class GlobalLock : public GlobalLockPod {
  public:
   GlobalLock();
 };
 
 // GlobalLockScope, for serializing execution through a scope.
 class SCOPED_LOCKABLE GlobalLockScope {
  public:
   explicit GlobalLockScope(GlobalLockPod* lock) EXCLUSIVE_LOCK_FUNCTION(lock);
   ~GlobalLockScope() UNLOCK_FUNCTION();
  private:
   GlobalLockPod* const lock_;
   RTC_DISALLOW_COPY_AND_ASSIGN(GlobalLockScope);
 };
 
 } // namespace rtc
 
 #endif // WEBRTC_BASE_CRITICALSECTION_H_