GitLab

It introduces wayland_util.cc/h and moves the code to create shared
memory buffer and draw bitmap on it from WaylandCursor, as it could
be used generally rather than specific to cursor area.
On upcoming patch for drag and drop on Wayland, it's also required
to pass the drag icon surface to Wayland.

It doesn't bring behavioral changes.

Bug: 578890, 875164
Change-Id: I0cd4603c2abacaa899a9fcf19d97186d6f493146
Reviewed-on: https://chromium-review.googlesource.com/1179487
Commit-Queue: Julie Jeongeun Kim <jkim@igalia.com>
Reviewed-by: Antonio Gomes <tonikitoo@igalia.com>
Reviewed-by: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/master@{#584328}