Function startPhaseTimer

docs/external/js/react-dom.development.js:10574–10589

(fiber, phase)

    }
  }
  function startPhaseTimer(fiber, phase) {
    {
      if (!supportsUserTiming) {
        return;
      }

      clearPendingPhaseMeasurement();

      if (!beginFiberMark(fiber, phase)) {
        return;
      }

      currentPhaseFiber = fiber;
      currentPhase = phase;
    }
  }
  function stopPhaseTimer() {
    {
      if (!supportsUserTiming) {