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

mojo/gles2/command_buffer_client_impl.cc

 // Copyright 2014 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 "mojo/gles2/command_buffer_client_impl.h"
 
 #include <limits>
 
 #include "base/logging.h"
 #include "base/process/process_handle.h"
@@ skipping 395 matching lines @@
 }
 
 gpu::CommandBufferNamespace CommandBufferClientImpl::GetNamespaceID() const {
   return gpu::CommandBufferNamespace::MOJO;
 }
 
 uint64_t CommandBufferClientImpl::GetCommandBufferID() const {
   return sync_client_impl_->GetCommandBufferID();
 }
 
-int32_t CommandBufferClientImpl::GetExtraCommandBufferData() const {
-  return 0;
-}
-
 uint64_t CommandBufferClientImpl::GenerateFenceSyncRelease() {
   return next_fence_sync_release_++;
 }
 
 bool CommandBufferClientImpl::IsFenceSyncRelease(uint64_t release) {
   return release != 0 && release < next_fence_sync_release_;
 }
 
 bool CommandBufferClientImpl::IsFenceSyncFlushed(uint64_t release) {
   return release != 0 && release <= flushed_fence_sync_release_;
@@ skipping 17 matching lines @@
 
   // It is also safe to wait on the same context.
   if (sync_token->namespace_id() == gpu::CommandBufferNamespace::MOJO &&
       sync_token->command_buffer_id() == GetCommandBufferID())
     return true;
 
   return false;
 }
 
 }  // namespace gles2