message: Metal backend: do a Tick() on queue submit.
diff: @@ -231,6 +231,7 @@ namespace backend { namespace metal {
  void Queue::Submit(uint32_t numCommands, CommandBuffer* const* commands) {
  Device* device = ToBackend(GetDevice());
  + device->Tick();
  id<MTLCommandBuffer> commandBuffer = device->GetPendingCommandBuffer();
  for (uint32_t i = 0; i < numCommands; ++i) {
  