Revert of Go back to old underline position and thickness logic

Revert of Go back to old underline position and thickness logic (patchset #2 id:20001 of https://codereview.chromium.org/550163003/)

Reason for revert:
Many tests failed on WinXP because of different underline position.

Original issue's description:
> 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
> R=scottmg@chromium.org, cpu@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181591

TBR=scottmg@chromium.org,cpu@chromium.org,eae@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=408075
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=181607

[keishi, 2014-09-09 05:08:04]

Created Revert of Go back to old underline position and thickness logic

[commit-bot: I haz the power, 2014-09-09 05:09:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/keishi@chromium.org/557653002/1

[commit-bot: I haz the power, 2014-09-09 05:09:36]

Committed patchset #1 (id:1) as 181607