The only reason the code used QSharedPointer is that it used QVector
to hold a collection of them, and QVector infamously cannot hold
move-only types such as std::unique_ptr.
Fix by using std::vector<std::unique_ptr> instead. Also, pass the
objeccts into non-sink functions by raw pointer instead of shared_ptr.
As a drive-by, replace clear-following-iterate by the for-exchanged
pattern.
Change-Id: I605fbb98af840c1b93eab9e65c07defd6e7b39e1
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>