D14668: [KCM GridDelegate] Use layer effect only on OpenGL backend

[Kai Uwe Broulik]

broulik edited the test plan for this revision.

REPOSITORY
  R296 KDeclarative

REVISION DETAIL
  https://phabricator.kde.org/D14668

To: broulik, #plasma, mart
Cc: kde-frameworks-devel, michaelh, ngraham, bruns