Revert of Added SyncToken command buffer trait to help with IPC messages.

gpu/command_buffer/common/sync_token.h

-// Copyright 2015 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_COMMON_SYNC_TOKEN_H_
-#define GPU_COMMAND_BUFFER_COMMON_SYNC_TOKEN_H_
-
-#include <stdint.h>
-
-#include "gpu/command_buffer/common/constants.h"
-#include "gpu/gpu_export.h"
-
-// From glextchromium.h.
-#ifndef GL_SYNC_TOKEN_SIZE_CHROMIUM
-#define GL_SYNC_TOKEN_SIZE_CHROMIUM 24
-#endif
-
-namespace gpu {
-
-// A Sync Token is a binary blob which represents a waitable fence sync
-// on a particular command buffer namespace and id.
-// See src/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_sync_point.txt for more
-// details.
-struct GPU_EXPORT SyncToken {
-  using Data = int8_t[GL_SYNC_TOKEN_SIZE_CHROMIUM];
-
-  SyncToken();
-  SyncToken(CommandBufferNamespace namespace_id,
-            uint64_t command_buffer_id,
-            uint64_t release_count);
-
-  CommandBufferNamespace GetNamespaceId() const;
-  uint64_t GetCommandBufferId() const;
-  uint64_t GetReleaseCount() const;
-
-  void SetData(CommandBufferNamespace namespace_id,
-               uint64_t command_buffer_id,
-               uint64_t release_count);
-
-  bool operator<(const SyncToken& other) const;
-
-  Data data;
-};
-
-}  // namespace gpu
-
-#endif  // GPU_COMMAND_BUFFER_COMMON_SYNC_TOKEN_H_
-