Enable CSS3 text decorations

Intent to Ship thread on blink-dev approved:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/d2mbqJ0ADXk

BUG=665898

Review-Url: https://codereview.chromium.org/2516333002
Cr-Commit-Position: refs/heads/master@{#433539}
3 files changed