command_buffer: Remove hash_tables.h, simplify atomicops.h

gpu/command_buffer/client/atomicops.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/client/atomicops.h"
 
 #include "base/logging.h"
 
 #if !defined(__native_client__)
 #include "base/atomicops.h"
 #include "base/synchronization/lock.h"
 #else
 #include <pthread.h>
 #endif
 
 namespace gpu {
 
-void MemoryBarrier() {
-#if defined(__native_client__)
-  __sync_synchronize();
-#else
-  base::subtle::MemoryBarrier();
-#endif
-}
-
 #if defined(__native_client__)
 
 class LockImpl {
  public:
   LockImpl()
        : acquired_(false) {
     pthread_mutex_init(&mutex_, NULL);
   }
 
   ~LockImpl() {
@@ skipping 55 matching lines @@
 bool Lock::Try() {
   return lock_->Try();
 }
 
 void Lock::AssertAcquired() const {
   return lock_->AssertAcquired();
 }
 
 }  // namespace gpu