Add mac_util, including MacOSXMinorVersion(), MacOSXVersion(), and MacModelAndBoard()

Add mac_util, including MacOSXMinorVersion(), MacOSXVersion(), and
MacModelAndBoard(), along with their tests.

TEST=util_test MacUtil.*
R=rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/8fe32b7b9c55

[Mark Mentovai, 2014-08-14 19:45:26]

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h
File util/mac/mac_util.h (right):

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h#newcode27
util/mac/mac_util.h:27: //! \note This is similar to the base::mac::IsOS*()
family of functions, but
bpoop is completely compatible with 10.5 except for one thing: it needs
bootstrap_register() on that OS only. Since the burden of supporting 10.5 is so
low here, I’ve gone ahead and done it. That’s why the IsOS*() family doesn’t
work here.

[Robert Sesek, 2014-08-15 21:31:54]

LGTM

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h
File util/mac/mac_util.h (right):

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h#newcode33
util/mac/mac_util.h:33: //! \brief Returns the version of the running operating
system.
Can I leave any of these NULL if I don't need the information?

[Mark Mentovai, 2014-08-16 05:30:48]

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h
File util/mac/mac_util.h (right):

https://codereview.chromium.org/473023002/diff/1/util/mac/mac_util.h#newcode33
util/mac/mac_util.h:33: //! \brief Returns the version of the running operating
system.
rsesek wrote:
> Can I leave any of these NULL if I don't need the information?

In the only cases I’ve had to call it, I needed all of the information, so I
didn’t write the NULL checks. I’ll document this. If you feel strongly that this
should tolerate NULL arguments, I can change it.

[Mark Mentovai, 2014-08-16 05:33:17]

Committed patchset #3 manually as 8fe32b7b9c55 (presubmit successful).