As suggested by comment 13 of the bug, the problem is caused
by commit b2486241 by Noel Grandin.

1. DocumentHolder::DocumentFrame(): XDesktop2 cannot be directly
queried for XFrame2. And in this case, simple XFrame is enough.

2. DocumentHolder::CloseFrame(): m_xFrame->dispose() violates an
assert because of NULL reference. Reverted to previous code.

3. Following commit debde4fd by
Andras Timar (supposed to fix the bug), found two places where
previously used to be UNO_QUERY, but now UNO_QUERY_THROW is used.
These places are reverted to use UNO_QUERY.

Change-Id: Ifb9e74367d5dd99ba12166abdd443b29a8018aeb
Reviewed-on: https://gerrit.libreoffice.org/15607Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Andras Timar <andras.timar@collabora.com>