CSS2:text-decoration: <rt> element should not inherit text-decoration property

CSS2:text-decoration: <rt> element should not inherit text-decoration property
https://bugs.webkit.org/show_bug.cgi?id=71266

Patch by Koji Ishii <kojiishi@gmail.com> on 2012-02-23
Reviewed by Kentaro Hara.

Source/WebCore:

Tests: fast/ruby/text-decoration-in-descendants-ruby-expected.html
       fast/ruby/text-decoration-in-descendants-ruby.html

The spec says "text decorations are not propagated to any out-of-flow descendants":
http://www.w3.org/TR/2011/WD-css3-text-20110901/#decoration
Floats etc. are fixed in bug 18611, but <rt> is not inline either and therefore
it should be included; it was confirmed at a discussion at www-style.
http://lists.w3.org/Archives/Public/www-style/2011Sep/0238.html

* rendering/RenderObject.cpp:
(WebCore::RenderObject::getTextDecorationColors):

LayoutTests:

The spec says "text decorations are not propagated to any out-of-flow descendants":
http://www.w3.org/TR/2011/WD-css3-text-20110901/#decoration
Floats etc. are fixed in bug 18611, but <rt> is not inline either and therefore
it should be included; it was confirmed at a discussion at www-style.
http://lists.w3.org/Archives/Public/www-style/2011Sep/0238.html

* fast/ruby/text-decoration-in-descendants-ruby-expected.html: Added.
* fast/ruby/text-decoration-in-descendants-ruby.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@108690 268f45cc-cd09-0410-ab3c-d52691b4dbfc