Fix failing of unittests in one thread

With change of default driver, that is used for unittests one additional
method 'ensure_share' was not mocked, that caused problems running
unittests in one thread.

Change-Id: Iea08207bb6200c37f5608d222dccdfbdc509b234
Closes-Bug: #1358854
Merge "Fix failing of unittests in one thread"