Update from https://crrev.com/316786

gpu/command_buffer/service/sync_point_manager.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 "gpu/command_buffer/service/sync_point_manager.h"
 
 #include <climits>
 
 #include "base/logging.h"
 #include "base/rand_util.h"
+#include "base/sequence_checker.h"
 
 namespace gpu {
 
 static const int kMaxSyncBase = INT_MAX;
 
-SyncPointManager::SyncPointManager()
+// static
+SyncPointManager* SyncPointManager::Create(bool allow_threaded_calls) {
+  return new SyncPointManager(allow_threaded_calls);
+}
+
+SyncPointManager::SyncPointManager(bool allow_threaded_calls)
     : next_sync_point_(base::RandInt(1, kMaxSyncBase)) {
   // To reduce the risk that a sync point created in a previous GPU process
   // will be in flight in the next GPU process, randomize the starting sync
   // point number. http://crbug.com/373452
+
+  if (!allow_threaded_calls) {
+    sequence_checker_.reset(new base::SequenceChecker);
+  }
 }
 
 SyncPointManager::~SyncPointManager() {
 }
 
 uint32 SyncPointManager::GenerateSyncPoint() {
   base::AutoLock lock(lock_);
   uint32 sync_point = next_sync_point_++;
   // When an integer overflow occurs, don't return 0.
   if (!sync_point)
     sync_point = next_sync_point_++;
 
   // Note: wrapping would take days for a buggy/compromized renderer that would
   // insert sync points in a loop, but if that were to happen, better explicitly
   // crash the GPU process than risk worse.
   // For normal operation (at most a few per frame), it would take ~a year to
   // wrap.
   CHECK(sync_point_map_.find(sync_point) == sync_point_map_.end());
   sync_point_map_.insert(std::make_pair(sync_point, ClosureList()));
   return sync_point;
 }
 
 void SyncPointManager::RetireSyncPoint(uint32 sync_point) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  CheckSequencedThread();
   ClosureList list;
   {
     base::AutoLock lock(lock_);
     SyncPointMap::iterator it = sync_point_map_.find(sync_point);
     if (it == sync_point_map_.end()) {
       LOG(ERROR) << "Attempted to retire sync point that"
                     " didn't exist or was already retired.";
       return;
     }
     list.swap(it->second);
     sync_point_map_.erase(it);
   }
   for (ClosureList::iterator i = list.begin(); i != list.end(); ++i)
     i->Run();
 }
 
 void SyncPointManager::AddSyncPointCallback(uint32 sync_point,
                                             const base::Closure& callback) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  CheckSequencedThread();
   {
     base::AutoLock lock(lock_);
     SyncPointMap::iterator it = sync_point_map_.find(sync_point);
     if (it != sync_point_map_.end()) {
       it->second.push_back(callback);
       return;
     }
   }
   callback.Run();
 }
 
 bool SyncPointManager::IsSyncPointRetired(uint32 sync_point) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  CheckSequencedThread();
   {
     base::AutoLock lock(lock_);
     SyncPointMap::iterator it = sync_point_map_.find(sync_point);
     return it == sync_point_map_.end();
   }
 }
 
+void SyncPointManager::CheckSequencedThread() {
+  DCHECK(!sequence_checker_ ||
+         sequence_checker_->CalledOnValidSequencedThread());
+}
+
 }  // namespace gpu