[rendering] Implement PaintInfo interfaces
https://bugs.webkit.org/show_bug.cgi?id=119388

Reviewed by Benjamin Poulain.

In discussion in IRC, it was decided to remove this comment since implementing such change
would have a vast impact on rendering classes.

* rendering/PaintInfo.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@153807 268f45cc-cd09-0410-ab3c-d52691b4dbfc