Fix READMEs to refer to the right test suite file.

BUG=
R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/49063003

git-svn-id: svn://svn.chromium.org/blink/trunk@160747 bbb929c8-8fbe-4397-9dbb-9b2b20218538