Function startPhaseTimer

lib/assets/react-source/development/react.js:14146–14161

(fiber, phase)

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

	    clearPendingPhaseMeasurement();

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

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