Update glyph tests to support subpixel font scaling

Update a couple of glyph tests to pass on platforms with subpixel font
scaling enabled.

R=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/335143009

git-svn-id: svn://svn.chromium.org/blink/trunk@176770 bbb929c8-8fbe-4397-9dbb-9b2b20218538