D5078: when the padding aroun the window changes, update

[Marco Martin]

mart edited the test plan for this revision.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D5078

To: mart, #plasma, graesslin
Cc: plasma-devel, kwin, #kwin, progwolff, lesliezhai, ali-mohamed, hardening, 
jensreuterberg, abetts, sebas, apol