Reviewed by Darin.

    Reviewed by Darin.

	<rdar://problem/3977973> pages on ebay leak referenced JavaScript objects -- over time browsing becomes super-slow

	I fixed this by removing all event listeners for a document, it's
	children, and any disconnected nodes that used to be in the
	document at document detach time. Mozilla temporarily disables
	event listeners on such nodes, but re-enables them if you
	re-parant a node into a new document. However, in WebCore, you
	can't re-parent a node into another document, so there is no
	observable change in behavior.

	We have to do this to break the possible reference cycles between
	event listeners and the dom nodes they are attached to (e.g. via
	scope chain, as in this case).

        * khtml/xml/dom_docimpl.cpp:
        (DocumentImpl::detach):
        (DocumentImpl::removeAllEventListenersFromAllNodesx):
        (DocumentImpl::registerDisconnectedNodeWithEventListeners):
        (DocumentImpl::unregisterDisconnectedNodeWithEventListeners):
        (DocumentImpl::removeAllDisconnectedNodeEventListeners):
        * khtml/xml/dom_docimpl.h:
        * khtml/xml/dom_nodeimpl.cpp:
        (NodeImpl::~NodeImpl):
        (NodeImpl::addEventListener):
        (NodeImpl::removeEventListener):
        (NodeImpl::removeAllEventListeners):
        (NodeImpl::removeHTMLEventListener):
        (NodeImpl::insertedIntoDocument):
        (NodeImpl::removedFromDocument):
        * khtml/xml/dom_nodeimpl.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8557 268f45cc-cd09-0410-ab3c-d52691b4dbfc