Remove all ShadowRoots during ElementShadow destruction
https://bugs.webkit.org/show_bug.cgi?id=108207

Reviewed by Dimitri Glazkov.

There's no reason to expose removeAllShadowRoots since the only legitimate
place to call it is right as we're destroying the ElementShadow.

No new tests, just refactoring.

* dom/Element.cpp:
(WebCore::Element::~Element): Remove call to removeAllShadowRoots()
* dom/ElementShadow.h:
(WebCore::ElementShadow::~ElementShadow): Call removeAllShadowRoots().
(ElementShadow): Make removeAllShadowRoots() private.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141162 268f45cc-cd09-0410-ab3c-d52691b4dbfc