Default to make generator on FreeBSD9 and 10 as well.
Default to make generator on FreeBSD9 and 10 as well.

Patch from Steve Wills <swills@freebsd.org>

Original code review at http://codereview.chromium.org/8574013/ .
Review URL: http://codereview.chromium.org/8587005
witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp,witwall/gyp