Disable virtual/.../updating-the-finished-state.html

Reason: Intermittent failures on Mac.

TBR=etiennep@chromium.org

Bug: 1029521
Change-Id: Ia0f4f3a74666de8db8c409f235bab9d610104586
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1943617Reviewed-by: Kevin Ellis <kevers@chromium.org>
Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Commit-Queue: Kevin Ellis <kevers@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720258}

third_party/blink/web_tests/TestExpectations

@@ -5910,3 +5910,5 @@ crbug.com/993790 external/wpt/document-policy/required-policy/required-document-
 
 # Temporary suppression to allow devtools-frontend changes
 crbug.com/1016772 http/tests/devtools/sourcemap-section-warning.js [ Pass Failure ]
+
+crbug.com/1029521 virtual/threaded/external/wpt/web-animations/timing-model/animations/updating-the-finished-state.html [ Pass Failure Timeout ]