GitLab

DataDevice-related wrappers initialization and ownership, for both
standard and GTK's primary selection, are quite confusing and spread
over different parts of the backend code. This CL fixes and simplifies
it by:

- Moving {WaylandData,GtkPrimarySelection}Device ownership to their
respective DataManager wrapper class. E.g: WaylandDataDeviceManager owns
WaylandDataDevice singleton;

- Fix WaylandClipboard initialization whether the compositor happens to
advertise GtkPrimarySelectionDeviceManager after wl_seat and
wl_data_device_manager;

- Use dependency injection to provide DataSources with the correct
DataDevice instance at their construction time;

- Clean up WaylandConnection by getting rid of the multiple (and almost
unused) data device getters from it as well as removing unneeded header
includes.

Bug: 896640
Change-Id: Ie12964fdf4e7b78bbbd9a11e133ab082613f1c7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2216320Reviewed-by: Maksim Sisov <msisov@igalia.com>
Commit-Queue: Nick Yamane <nickdiego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#773235}