Fix crash in the cairo implementation of the SVGPaintServer

For SVGFonts the RenderObject can be zero. The existing SVGFont
test cases is exposing this bug. Qt and other ports have fixed
this issue by adding null checks as well.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@39208 268f45cc-cd09-0410-ab3c-d52691b4dbfc
2 files changed