Additional timeout expectations for threaded animations tests.

These two additional tests are flakey on Win.

TBR=
BUG=248938

Review URL: https://codereview.chromium.org/83933002

git-svn-id: svn://svn.chromium.org/blink/trunk@162557 bbb929c8-8fbe-4397-9dbb-9b2b20218538