Gardening: fast/canvas/2d.text.draw.fill.maxWidth.gradient.html flaky

BUG=245644
TEST=
TBR=zmo@chromium.org

Review URL: https://codereview.chromium.org/204083002

git-svn-id: svn://svn.chromium.org/blink/trunk@169487 bbb929c8-8fbe-4397-9dbb-9b2b20218538