DevTools: await the result of protocol messages in animation-release.js

Bug: 1028684
Change-Id: If579db7684970205d55a398016b55b889bb3e7bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1978748
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728154}

third_party/blink/web_tests/inspector-protocol/animation/animation-release.js

@@ -3,21 +3,23 @@
     <div id='node' style='background-color: red; width: 100px'></div>
   `, 'Tests that the animation is correctly paused.');
 
-  dp.Animation.enable();
-  session.evaluate(`
+  await dp.Animation.enable();
+
+  const animationStartedPromise = dp.Animation.onceAnimationStarted();
+  await session.evaluate(`
     window.animation = node.animate([{ width: '100px' }, { width: '2000px' }], { duration: 0, fill: 'forwards' });
   `);
 
-  var id = (await dp.Animation.onceAnimationStarted()).params.animation.id;
+  var id = (await animationStartedPromise).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()');
+  await dp.Animation.setPaused({ animations: [ id ], paused: true });
+  await 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 ] });
+  await dp.Animation.releaseAnimations({ animations: [ id ] });
   width = await session.evaluate('node.offsetWidth');
   testRunner.log('Animation released');
   testRunner.log('Box is animating: ' + (width != 100).toString());