Revert "Refactoring: Make gtest testsuite the default."

This reverts commit cb8f08658767e7e3182e5deab0473f264f6ce92f.

TBR=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/532673002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23584 ce2b1a6d-e550-0410-aec6-3dcde31c8c00