With r1627 (http://code.google.com/p/v8/source/detail?r=1627) the use of the debugger message thread was made optional. However the check for active debugger still included a check for the message thread. This is fixed by this change.
Review URL: http://codereview.chromium.org/58001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1637 ce2b1a6d-e550-0410-aec6-3dcde31c8c00