https://bugs.webkit.org/show_bug.cgi?id=82607

Reviewed by Hajime Morita.

.:

* Source/autotools/symbols.filter:

Source/WebCore:

DOMSelection didn't consider nested shadow trees. This patch makes DOMSelection
take nested shadow trees into account.

To test that the element is not in a shadow tree, Internals has a treeScopeRootNode method
which returns the root node of the belonging tree scope.

Test: fast/dom/shadow/selection-shouldnt-expose-shadow-dom.html

* WebCore.exp.in:
* page/DOMSelection.cpp:
(WebCore::selectionShadowAncestor):
(WebCore):
* testing/Internals.cpp:
(WebCore::Internals::treeScopeRootNode):
(WebCore):
* testing/Internals.h:
(Internals):
* testing/Internals.idl:

Source/WebKit2:

* win/WebKit2.def:
* win/WebKit2CFLite.def:

LayoutTests:

* fast/dom/shadow/selection-shouldnt-expose-shadow-dom-expected.txt: Added.
* fast/dom/shadow/selection-shouldnt-expose-shadow-dom.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@113276 268f45cc-cd09-0410-ab3c-d52691b4dbfc