Reviewed by Brady Eidson.

        Add back/forward encoding and decoding to WebKit2
        https://bugs.webkit.org/show_bug.cgi?id=51901

        * WebCore.exp.in: Export functions used in WebKit2.

        * history/HistoryItem.cpp:
        (WebCore::HistoryItem::encodeBackForwardTree): Use references instead of pointers.
        (WebCore::HistoryItem::encodeBackForwardTreeNode): Ditto.
        (WebCore::HistoryItem::decodeBackForwardTree): Ditto.
        * history/HistoryItem.h: Ditto.
        * platform/network/FormData.cpp:
        (WebCore::encode): Ditto.
        (WebCore::decode): Ditto.
        (WebCore::FormData::encodeForBackForward): Ditto.
        (WebCore::FormData::decodeForBackForward): Ditto.
        * platform/network/FormData.h: Ditto.
2011-01-04  Darin Adler  <darin@apple.com>

        Reviewed by Brady Eidson.

        Add back/forward encoding and decoding to WebKit2
        https://bugs.webkit.org/show_bug.cgi?id=51901

        * G...