Fix mistaken assumptions in tests

This test assumes that spinning the event loop is sufficient to trigger
asynchronous style recalculation. After we move style recalculation to be
triggered off requestAnimationFrame, this assumption will no longer be valid.
This CL removes this assumption by triggering layout explicitly

R=fsamuel@chromium.org
BUG=337617

Review URL: https://codereview.chromium.org/148153013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247563 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed