message: Don't spinlock when waiting for blocking render commands
diff: @@ -270,11 +270,7 @@ void RenderManager::BlockInvoke(RenderManager::InvokeMethod m)
  PushInvoke(cmd);
  - for(;;)
  - {
  - if(cmd->processed.tryAcquire())
  - break;
  - }
  + cmd->processed.acquire();
  delete cmd;
  }
  