D22755: [platforms/xcb] Use XRES extension to get real window PID

[Vlad Zagorodniy]

zzag accepted this revision.
This revision is now accepted and ready to land.

REPOSITORY
  R278 KWindowSystem

BRANCH
  master

REVISION DETAIL
  https://phabricator.kde.org/D22755

To: davidedmundson, zzag
Cc: kde-frameworks-devel, LeGast00n, sbergeron, michaelh, ngraham, bruns