SelectorChecker::parentElement should walk up to ShadowHost only if an element is in a shadow tree …

SelectorChecker::parentElement should walk up to ShadowHost only if an element is in a shadow tree hosted by the ShadowHost and scope is the ShadowHost.

:host can only match shadow host. :host depends on context.scope with ScopeIsShadowHost behavior.
So only if context.scope is shadow host and context.element's shadow host is context.scope, we need to check the shadow host.

BUG=370303
TEST=fast/dom/shadow/style-with-cat.html, fast/dom/shadow/style-with-hat.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173703

[tasak, 2014-05-08 10:47:14]

Would you review this CL?

[dglazkov, 2014-05-08 19:21:48]

lgtm.

We really ought to look at rewriting this logic. All of these conditions are the
albatross.

[tasak, 2014-05-09 02:13:29]

Thank you for reviewing.

[tasak, 2014-05-09 02:13:34]

The CQ bit was checked by tasak@google.com

[commit-bot: I haz the power, 2014-05-09 02:15:38]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tasak@google.com/273523008/1

[commit-bot: I haz the power, 2014-05-09 02:30:52]

Change committed as 173703