container, so we can't query for a webshell interface and query if scrolling is
implemented. With isScrolling set to PR_TRUE, we then follow code below which
leads to a crash. Fixes crash seen often when performing Postscript printing on
Unix.
Reviewed by dcone.
git-svn-id: svn://10.0.0.236/trunk@25538 18797224-902f-48f8-a5cc-f745e15eee43