Revert of Added an extra sync token field for extra command buffer identification.

ppapi/proxy/ppapi_command_buffer_proxy.h

 // 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 PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 #define PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_
 
 #include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 57 matching lines @@
   bool IsGpuChannelLost() override;
   gpu::CommandBufferNamespace GetNamespaceID() const override;
   uint64_t GetCommandBufferID() const override;
   uint64_t GenerateFenceSyncRelease() override;
   bool IsFenceSyncRelease(uint64_t release) override;
   bool IsFenceSyncFlushed(uint64_t release) override;
   bool IsFenceSyncFlushReceived(uint64_t release) override;
   void SignalSyncToken(const gpu::SyncToken& sync_token,
                        const base::Closure& callback) override;
   bool CanWaitUnverifiedSyncToken(const gpu::SyncToken* sync_token) override;
-  int32_t GetExtraCommandBufferData() const override;
 
  private:
   bool Send(IPC::Message* msg);
   void UpdateState(const gpu::CommandBuffer::State& state, bool success);
 
   // Try to read an updated copy of the state from shared memory.
   void TryUpdateState();
 
   // The shared memory area used to update state.
   gpu::CommandBufferSharedState* shared_state() const;
@@ skipping 17 matching lines @@
   uint64_t pending_fence_sync_release_;
   uint64_t flushed_fence_sync_release_;
 
   DISALLOW_COPY_AND_ASSIGN(PpapiCommandBufferProxy);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif // PPAPI_PROXY_COMMAND_BUFFER_PROXY_H_