D18261: support decorations from lookandfeel

mart added inline comments.

INLINE COMMENTS

> davidedmundson wrote in decorationbridge.cpp:85
> This local var is effectively unused.
> "plugin" isn't a very helpful name as there are 3 potential plugins mentioned in this method.
> 
> It'll be clearer if the last line just uses s_defaultPlugin directly
> 
> I would also avoid "cg" because kwinApp->config() is also a cg.
> 
> This also applies for readTheme

maybe by rewriting s_defaultTheme in the DecorationBridge ctor?

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D18261

To: mart, #plasma, #kwin
Cc: davidedmundson, kwin, jraleigh, GB_2, mkulinski, ragreen, jackyalcine, Pitel, iodelay, bwowk, ZrenBot, ngraham, lesliezhai, ali-mohamed, hardening, jensreuterberg, abetts, sebas, apol, mart