D11069: [WIP] refine decoration shadows

[Vlad Zagorodniy]

zzag edited the summary of this revision.

REPOSITORY
  R31 Breeze

REVISION DETAIL
  https://phabricator.kde.org/D11069

To: zzag, #breeze, #vdg
Cc: plasma-devel, ZrenBot, lesliezhai, ali-mohamed, jensreuterberg, abetts, 
sebas, apol, mart