Move CloudFileService::ShowContextMenu to the base class so that all
services can utilize the pattern established in CloudFileService.
ShowContextMenu creates the menu if it doesn't exist then calls an
overridable method to populate the content. It then calls an update
method before showing the menu.
Add PopulateContextMenu, called once to populate the menu items, and
UpdateContextMenu, called ever time a menu is shown, to allow
service-specific behavior.
A LibraryBackend may be deleted while an associated LibraryModel object is using
it. An example is an async query running while a connected device is removed.
To prevent this, use a share pointer for the LibraryBackend.
This fixes one case where LibraryBackend is used after deletion. However, the
raw pointer is still passed around in several other places. These should be
evaluated on a case-by-case basis to insure that circular depencencies aren't
introduced.
Jim Broadus
kentsangkm
Jim Broadus
John Maguire
Chocobozzz
Krzysztof Sobiecki