Update web-platform-tests to revision 2d42384cf21efd71843295d319c1bab85b3acf4a

tests/wpt/web-platform-tests/animation-worklet/common.js

@@ -0,0 +1,33 @@
+'use strict';
+
+function registerPassthroughAnimator() {
+  return runInAnimationWorklet(`
+    registerAnimator('passthrough', class {
+      animate(currentTime, effect) { effect.localTime = currentTime; }
+    });
+  `);
+}
+
+function runInAnimationWorklet(code) {
+  return CSS.animationWorklet.addModule(
+    URL.createObjectURL(new Blob([code], {type: 'text/javascript'}))
+  );
+}
+
+function waitForAnimationFrames(count, callback) {
+  function rafCallback() {
+    if (count <= 0) {
+      callback();
+    } else {
+      count -= 1;
+      window.requestAnimationFrame(rafCallback);
+    }
+  }
+  rafCallback();
+};
+
+// Wait for two main thread frames to guarantee that compositor has produced
+// at least one frame. Note that this is a Chrome-only concept.
+function waitTwoAnimationFrames(callback) {
+  waitForAnimationFrames(2, callback);
+};