Function computeDisplay

src/utils/display-observer.js:414–423

* @param {?Array } observations * @param {boolean} isDocDisplay * @return {?boolean}

(observations, isDocDisplay)

 * @return {?boolean}
 */
function computeDisplay(observations, isDocDisplay) {
  if (!isDocDisplay) {
    return false;
  }
  if (!observations || observations.length == 0) {
    // Unknown yet.
    return null;
  }
  return observations.reduce(displayReducer);
}

/**
 * @param {!VisibilityState_Enum} visibilityState