Two simple profiler changes: 1) log sampling rate, 2) check current state before pausing & resuming.

Review URL: http://codereview.chromium.org/113961


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2073 ce2b1a6d-e550-0410-aec6-3dcde31c8c00