Reland "Go back to old underline position and thickness logic"

In r174431 from May this year we changed the underline position and
thickness logic to respect the underline data specified in the font.
While this improved rendering for certain fonts and scripts it did cause
a regression for others. This change reverts to the old behavior while
we figure out how to handle fonts with inaccurate or undesirable
metrics.

BUG=408075
TBR=keishi@chromium.org

Committed as r181591 and reverted in r181607 due to missing XP
expectations.

Review URL: https://codereview.chromium.org/555883002

git-svn-id: svn://svn.chromium.org/blink/trunk@181659 bbb929c8-8fbe-4397-9dbb-9b2b20218538