Gardening: fast/text/international/text-combine-image-test.html is flaky

BUG=312606
TBR=dglazkov

Review URL: https://codereview.chromium.org/50453002

git-svn-id: svn://svn.chromium.org/blink/trunk@160812 bbb929c8-8fbe-4397-9dbb-9b2b20218538