third_party/WebKit/LayoutTests/fast/dom/MutationObserver/observer-wrapper-dropoff-transient.html

   1 <!DOCTYPE html>
   2
   3 <script src="../../../resources/js-test.js"></script>
   4
   5 <script>
   6 description('MutationObserver wrappers should survive GC for passing into the callback even if JS has lost references and the only remaining observations are transient.');
   7
   8 jsTestIsAsync = true;
   9
  10 function addObserver(node, fn) {
  11     var observer = new MutationObserver(fn);
  12     observer.testProperty = true;
  13     observer.observe(node, {attributes:true, subtree: true});
  14 }
  15
  16 onload = function() {
  17     var root = document.createElement('div');
  18     var child = root.appendChild(document.createElement('span'));
  19     addObserver(root, function(records, observer) {
  20         window.observer = observer;
  21         shouldBe('observer.testProperty', 'true');
  22         finishJSTest();
  23     });
  24
  25     root.removeChild(child);
  26     child.setAttribute('foo', 'bar');
  27     root = null;
  28
  29     gc();
  30 };
  31 </script>
  32