Extend timeout in worklet-animation-local-time-null-2

Fixes flakiness due to a cause it is not supposed to be testing for.

Bug: 1115277
Change-Id: I41d43339913577ef20cabf528d6d1934baab3197
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2350488
Commit-Queue: George Steel <gtsteel@chromium.org>
Commit-Queue: Alex Russell <slightlyoff@chromium.org>
Reviewed-by: Alex Russell <slightlyoff@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797042}

third_party/blink/web_tests/external/wpt/animation-worklet/worklet-animation-local-time-null-2.https.html

@@ -3,6 +3,7 @@
 <title>Setting localTime to null means effect does not apply (reftest)</title>
 <link rel="help" href="https://drafts.css-houdini.org/css-animationworklet/">
 <link rel="match" href="worklet-animation-local-time-null-2-ref.html">
+<meta name="timeout" content="long">
 
 <script src="/common/reftest-wait.js"></script>
 <script src="/web-animations/testcommon.js"></script>
@@ -100,7 +101,8 @@ runInAnimationWorklet(`
   ]);
 
   waitForAnimationFrameWithCondition(() => control_anim.currentTime > 1000)
-    .then(() => waitForAsyncAnimationFrames(1))
+    // long timeout due to laggy compositor thread on debug build.
+    .then(() => waitForAsyncAnimationFrames(120))
     .then(takeScreenshot);
 });