Release the reference to the HTMLPlugInElement's script object, when the element is removed from the document.  This breaks a cyclical reference that would otherwise cause the element to be retained until the document is torn down.
https://bugs.webkit.org/show_bug.cgi?id=66181

Patch by James Weatherall <wez@chromium.org> on 2011-09-08
Reviewed by Anders Carlsson.

No new tests - no functional change.

* html/HTMLPlugInElement.cpp:
(WebCore::HTMLPlugInElement::removedFromDocument):
* html/HTMLPlugInElement.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@94831 268f45cc-cd09-0410-ab3c-d52691b4dbfc