I noticed a funny thing: in StackTracer::Trace "sample.state" is
checked, but it is only assigned after the check. I've put assignment
before the check.

Review URL: http://codereview.chromium.org/660452

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4017 ce2b1a6d-e550-0410-aec6-3dcde31c8c00