[webkit-dev] Adding the first reference combinator behind a SHADOW_DOM flag

[Hayato Ito]

Hi,

I'd like to add support for a select reference combinator behind a
SHADOW_DOM flag.
https://bugs.webkit.org/show_bug.cgi?id=82169

The spec for this feature:
  - Selectors Level 4 specification
    http://dev.w3.org/csswg/selectors4/#idref-combinators
  - Shadow DOM specification
    http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/shadow/index.html#selecting-nodes-distributed-to-insertion-points

Since a select reference combinator will be the first reference
combinator implemented in WebKit, this will introduces a new CSS
grammer behind a SHADOW_DOM flag.

Please let me know of any concerns.


-- 
Hayato