(See go/owp-launch-guide for an overview)
Add a textDecoration attribute to canvas 2D contexts, behavior similar to existing "font" attribute: It's a DOMString, parsed the same way as corresponding CSS property (text-decoration).
Changes to API surface:
WebKit bug: crbug.com/164011
Public standards discussion: http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org//2013-April/039392.html
Support in other browsers: current (expected)
Internet Explorer: None
Unclear if others will support; working on experimental branch for now to get this on standards track.