virtual/threaded/.../paint2d-image.https.html timeouts on Mac bots.

Sample failure:
https://ci.chromium.org/p/chromium/builders/ci/Mac10.13%20Tests/12814

TBR: xidachen@chromium.org
No-Try: True
Bug: 957457
Change-Id: Ie8c6f89dfc9eb61ed1d0f21ce67c0da5ad5f4be2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1589231
Reviewed-by: Ella Ge <eirage@chromium.org>
Commit-Queue: Ella Ge <eirage@chromium.org>
Cr-Commit-Position: refs/heads/master@{#655277}
1 file changed