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<!DOCTYPE HTML>
<html>
<head>
  <title>Test hit-testing on content which is revealed by async scrolling</title>
  <script type="application/javascript" src="apz_test_utils.js"></script>
  <script type="application/javascript" src="apz_test_native_event_utils.js"></script>
  <script src="/tests/SimpleTest/paint_listener.js"></script>
  <meta name="viewport" content="width=device-width"/>
  <style>
    #parent {
      width: 400px;
      height: 400px;
      overflow: auto;
    }
    #child {
      margin-top: 200px;
      width: 100%;
      height: 100px;
      overflow: auto;
    }
    #obscurer {
      position: absolute;
      top: 200px;
      width: 400px;
      height: 200px;
      background: blue;
    }
    .spacer {
      width: 100%;
      height: 1000px;
      background: green;
    }
  </style>
</head>
<body>
  <div id="parent">
    <div id="child">
      <div class="spacer"></div>
    </div>
    <div class="spacer"></div>
  </div>
  <div id="obscurer"></div>
</body>
<script type="application/javascript">
async function test() {
  var config = getHitTestConfig();
  var utils = config.utils;
  // Create APZCs for parent and child scrollers.
  let parent = document.getElementById("parent");  // otherwise parent refers to window.parent
  utils.setDisplayPortForElement(0, 0, 400, 1000, parent, 1);
  utils.setDisplayPortForElement(0, 0, 400, 1000, child, 1);
  await promiseApzFlushedRepaints();
  // Async-scroll the parent scroller by 100 pixels, thereby revealing
  // the child which was previous covered by "obscurer".
  utils.setAsyncScrollOffset(parent, 0, 100);
  // Give WebRender a chance to sample the test async scroll offset.
  utils.advanceTimeAndRefresh(16);
  utils.restoreNormalRefresh();
  // Check that hit-testing on the region where the child scroller's
  // contents are now revealed, successfully hits the scroller.
  checkHitResult(hitTest({x: 200, y: 150}),
                 APZHitResultFlags.VISIBLE,
                 utils.getViewId(child),
                 utils.getLayersId(),
                 "child scroller");
}
waitUntilApzStable()
.then(test)
.then(subtestDone, subtestFailed);
</script>
</html>