BUG=
TEST=release test-api MultipleIsolatesOnIndividualThreads on Windows X64 build.

Review URL: http://codereview.chromium.org/6777007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7437 ce2b1a6d-e550-0410-aec6-3dcde31c8c00