Function markUpdate

code/event-handlers/public/app.js:9898–9902

(workInProgress)

  function markUpdate(workInProgress) {
    // Tag the fiber with an update effect. This turns a Placement into
    // an UpdateAndPlacement.
    workInProgress.effectTag |= Update;
  }

  function markRef(workInProgress) {
    workInProgress.effectTag |= Ref;