IntersectionObserver: convert tests to testharness.js

third_party/WebKit/LayoutTests/resources/intersection-observer-helper-functions.js

-// Some of the js-test.js boilerplate will add stuff to the top of the document early
-// enough to screw with frame offsets that are measured by the test.  Delay all that
-// jazz until the actual test code is finished.
-if (self.isJsTest) {
-  setPrintTestResultsLazily();
-  self.jsTestIsAsync = true;
-}
-
-// waitForNotification is a setTimeout wrapped in a setTimeout wrapped in a
-// requestAnimationFrame.  What in the wide, wide world of sports is going on here?
-//
-// Here's the order of events:
-//
-// - firstTestFunction
-//   - Change layout to generate new IntersectionObserver notifications.
-//   - waitForNotification(secondTestFunction)
-//     - requestAnimationFrame
-// - BeginFrame
-//   - requestAnimationFrame handler runs.
-//     - queue first setTimeout
-//   - FrameView::updateAllLifecyclePhases
-//     - IntersectionObserver generates notification based on the new layout.
-//       - Post task to deliver notification.
-//   - first setTimeout runs.
-//     - queue second setTimeout
-//   - Posted task runs.
-//     - IntersectionObserver notifications are delivered.
-//   - second setTimeout runs secondTestFunction
-//     - Verify notifications generated by firstTestFunction.
-//     - Change layout to generate new IntersectionObserver notifications.
-//     - waitForNotification(thirdTestFunction)
-function waitForNotification(f) {
-  requestAnimationFrame(() => {
-    setTimeout(() => {
-      setTimeout(f);
-    });
-  });
-}
-
-function rectToString(rect) {
-  return "[" + rect.left + ", " + rect.right + ", " + rect.top + ", " + rect.bottom + "]";
-}
-
-function entryToString(entry) {
-  var ratio = ((entry.intersectionRect.width * entry.intersectionRect.height) /
-               (entry.boundingClientRect.width * entry.boundingClientRect.height));
-  return (
-      "boundingClientRect=" + rectToString(entry.boundingClientRect) + "\n" +
-      "intersectionRect=" + rectToString(entry.intersectionRect) + "\n" +
-      "visibleRatio=" + ratio + "\n" +
-      "rootBounds=" + rectToString(entry.rootBounds) + "\n" +
-      "target=" + entry.target + "\n" +
-      "time=" + entry.time);
-}
-
-function rectArea(rect) {
-  return (rect.left - rect.right) * (rect.bottom - rect.top);
-}
-
-function intersectionRatio(entry) {
-  var targetArea = rectArea(entry.boundingClientRect);
-  if (!targetArea)
-    return 0;
-  return rectArea(entry.intersectionRect) / targetArea;
-}
-
-function clientRectToJson(rect) {
-  if (!rect)
-    return null;
-  return {
-    top: rect.top,
-    right: rect.right,
-    bottom: rect.bottom,
-    left: rect.left,
-    width: rect.width,
-    height: rect.height
-  };
-}
-
-function coordinatesToClientRectJson(top, right, bottom, left) {
-  return {
-    top: top,
-    right: right,
-    bottom: bottom,
-    left: left,
-    width: right - left,
-    height: bottom - top
-  };
-}
-
-function entryToJson(entry) {
-  return {
-    boundingClientRect: clientRectToJson(entry.boundingClientRect),
-    intersectionRect: clientRectToJson(entry.intersectionRect),
-    rootBounds: clientRectToJson(entry.rootBounds),
-    time: entry.time,
-    target: entry.target.id
-  };
-}