[DevTools] New harness for inspector-protocol layout tests

third_party/WebKit/LayoutTests/inspector-protocol/animation/animation-release.js

+(async function(testRunner) {
+  let {page, session, dp} = await testRunner.startHTML(`
+    <div id='node' style='background-color: red; width: 100px'></div>
+  `, 'Tests that the animation is correctly paused.');
+
+  dp.Animation.enable();
+  session.evaluate(`
+    window.animation = node.animate([{ width: '100px' }, { width: '2000px' }], { duration: 0, fill: 'forwards' });
+  `);
+
+  var id = (await dp.Animation.onceAnimationStarted()).params.animation.id;
+  testRunner.log('Animation started');
+  var width = await session.evaluate('node.offsetWidth');
+  testRunner.log('Box is animating: ' + (width != 100).toString());
+  dp.Animation.setPaused({ animations: [ id ], paused: true });
+  session.evaluate('animation.cancel()');
+  width = await session.evaluate('node.offsetWidth');
+  testRunner.log('Animation paused');
+  testRunner.log('Box is animating: ' + (width != 100).toString());
+  dp.Animation.releaseAnimations({ animations: [ id ] });
+  width = await session.evaluate('node.offsetWidth');
+  testRunner.log('Animation released');
+  testRunner.log('Box is animating: ' + (width != 100).toString());
+  testRunner.completeTest();
+})