Rebaseline fast/text/sub-pixel/text-scaling-pixel.html

Rebaseline results for fast/text/sub-pixel/text-scaling-pixel.html
following the test change in r172562.

TBR=jsbell@chromium.org

Review URL: https://codereview.chromium.org/250953007

git-svn-id: svn://svn.chromium.org/blink/trunk@172766 bbb929c8-8fbe-4397-9dbb-9b2b20218538