Function markUpdate

code/styling/public/app.js:10568–10572

(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;