Added method to synchronize command buffers within GpuControl.

ppapi/proxy/ppapi_command_buffer_proxy.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 "ppapi/proxy/ppapi_command_buffer_proxy.h"
 
 #include <utility>
 
 #include "base/numerics/safe_conversions.h"
 #include "ppapi/proxy/ppapi_messages.h"
@@ skipping 165 matching lines @@
 
 void PpapiCommandBufferProxy::SetLock(base::Lock*) {
   NOTIMPLEMENTED();
 }
 
 bool PpapiCommandBufferProxy::IsGpuChannelLost() {
   NOTIMPLEMENTED();
   return false;
 }
 
+void PpapiCommandBufferProxy::EnsureWorkVisible() {
+  NOTIMPLEMENTED();
+}
+
 gpu::CommandBufferNamespace PpapiCommandBufferProxy::GetNamespaceID() const {
   return gpu::CommandBufferNamespace::GPU_IO;
 }
 
 uint64_t PpapiCommandBufferProxy::GetCommandBufferID() const {
   return command_buffer_id_;
 }
 
 uint64_t PpapiCommandBufferProxy::GenerateFenceSyncRelease() {
   return next_fence_sync_release_++;
 }
 
 bool PpapiCommandBufferProxy::IsFenceSyncRelease(uint64_t release) {
   return release != 0 && release < next_fence_sync_release_;
 }
 
 bool PpapiCommandBufferProxy::IsFenceSyncFlushed(uint64_t release) {
   return release <= flushed_fence_sync_release_;
 }
 
 bool PpapiCommandBufferProxy::IsFenceSyncFlushReceived(uint64_t release) {
+  // TODO(dyen): This needs a synchronous NOP to the PpapiHost which
+  // also sends a synchronous NOP to the actual server.
   return IsFenceSyncFlushed(release);
 }
 
 void PpapiCommandBufferProxy::SignalSyncToken(const gpu::SyncToken& sync_token,
                                               const base::Closure& callback) {
   NOTIMPLEMENTED();
 }
 
 bool PpapiCommandBufferProxy::CanWaitUnverifiedSyncToken(
     const gpu::SyncToken* sync_token) {
@@ skipping 119 matching lines @@
   message->set_unblock(true);
   Send(message);
 
   flush_info_->flush_pending = false;
   flush_info_->resource.SetHostResource(0, 0);
   flushed_fence_sync_release_ = pending_fence_sync_release_;
 }
 
 }  // namespace proxy
 }  // namespace ppapi