Use return value of GetPropertyAttributes to make compiler happy.

BUG=
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/420443006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22638 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
[Auto-roll] Bump up version to 3.28.44.0

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/422003002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22639 ce2b1a6d-e550-0410-aec6-3dcde31c8c00