Apply custom property animations

third_party/WebKit/LayoutTests/animations/custom-properties/element-animate-crash.html

-<script src="../resources/testharness.js"></script>
-<script src="../resources/testharnessreport.js"></script>
+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
 <div id="target"></div>
 <script>
 promise_test(() => {
   return new Promise(resolve => {
     target.animate([
       {'resize':'none'},
       {'resize':'none'},
     ], {
       duration: 1000,
       delay: 100,
     });
     target.animate([
       {'--custom-property-name':'custom-value'},
       {'--custom-property-name':'custom-value'},
     ], 1);
     // This specific combination of async behaviour is required to trigger the crash,
     // creating functions here prevents the crash. This is probably due to V8 GC
     // implementation details.
     setInterval(gc);
     setTimeout(resolve);
   });
 }, 'Do not crash in ASAN when using custom properties in element.animate()');
 </script>