gpu: Thread-safe command buffer state lookup.

gpu/ipc/service/gpu_command_buffer_stub.cc

Index: gpu/ipc/service/gpu_command_buffer_stub.cc
diff --git a/gpu/ipc/service/gpu_command_buffer_stub.cc b/gpu/ipc/service/gpu_command_buffer_stub.cc
index b6396195afabdcb5ec8d6c46d8e5f253f00e02fe..3986ecf8629545ce21e926878c20fbf60e581916 100644
--- a/gpu/ipc/service/gpu_command_buffer_stub.cc
+++ b/gpu/ipc/service/gpu_command_buffer_stub.cc
@@ -948,6 +948,7 @@ void GpuCommandBufferStub::OnFenceSyncRelease(uint64_t release) {
   }
 
   sync_point_client_->ReleaseFenceSync(release);
+  command_buffer_->SetReleaseCount(release);

[piman, 2016/12/02 19:21:48]

nit: do this before ReleaseFenceSync, to ensure consistency -
sync_point_client_->ReleaseFenceSync will call callbacks and stuff (e.g.
SignalSyncToken's), so this would make sure that by the time they run
IsFenceSyncReleased() would return true.

[sunnyps, 2016/12/07 03:31:22]

Done.

 }
 
 void GpuCommandBufferStub::OnDescheduleUntilFinished() {