Reviewed by Chris Fleizach.

        Computing style on a stale node while sending pending accessibility notification.
        https://bugs.webkit.org/show_bug.cgi?id=50162

        Retain node pointer members of AccessibilityImageMapLink.

        Test: accessibility/image-map-title-causes-crash.html

        * accessibility/AccessibilityImageMapLink.cpp:
        (WebCore::AccessibilityImageMapLink::parentObject):
        (WebCore::AccessibilityImageMapLink::anchorElement):
        (WebCore::AccessibilityImageMapLink::url):
        (WebCore::AccessibilityImageMapLink::elementRect):
        * accessibility/AccessibilityImageMapLink.h:
        (WebCore::AccessibilityImageMapLink::areaElement):
        (WebCore::AccessibilityImageMapLink::mapElement):
        (WebCore::AccessibilityImageMapLink::node):
        * dom/Document.cpp:
        (WebCore::Document::clearAXObjectCache):
2010-11-30  Chris Guillory  <chris.guillory@google.com>

        Re...