gpu: Add sync token dependencies to flush metadata.

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 196 matching lines @@
 bool PpapiCommandBufferProxy::IsFenceSyncReleased(uint64_t release) {
   NOTIMPLEMENTED();
   return false;
 }
 
 void PpapiCommandBufferProxy::SignalSyncToken(const gpu::SyncToken& sync_token,
                                               const base::Closure& callback) {
   NOTIMPLEMENTED();
 }
 
+void PpapiCommandBufferProxy::WaitSyncTokenHint(
+    const gpu::SyncToken& sync_token) {
+  // TODO(sunnyps): Forward sync token dependency hints to the renderer.
+}
+
 bool PpapiCommandBufferProxy::CanWaitUnverifiedSyncToken(
-    const gpu::SyncToken* sync_token) {
+    const gpu::SyncToken& sync_token) {
   return false;
 }
 
 int32_t PpapiCommandBufferProxy::GetExtraCommandBufferData() const {
   return 0;
 }
 
 void PpapiCommandBufferProxy::SignalQuery(uint32_t query,
                                           const base::Closure& callback) {
   NOTREACHED();
@@ skipping 75 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