Move gpu hash_tables and atomicops stuff

gpu/command_buffer/client/atomicops.h

Index: gpu/command_buffer/client/atomicops.h
diff --git a/gpu/command_buffer/client/atomicops.h b/gpu/command_buffer/client/atomicops.h
new file mode 100644
index 0000000000000000000000000000000000000000..ffd274cf2a52ebbe4ac11de89c661d3c91d926c1
--- /dev/null
+++ b/gpu/command_buffer/client/atomicops.h
@@ -0,0 +1,14 @@
+// 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.
+
+#ifndef GPU_COMMAND_BUFFER_CLIENT_ATOMICOPS_H_
+#define GPU_COMMAND_BUFFER_CLIENT_ATOMICOPS_H_
+
+namespace gpu {
+
+void MemoryBarrier();
+
+}  // namespace gpu
+
+#endif  // GPU_COMMAND_BUFFER_CLIENT_ATOMICOPS_H_