10.10 SDK compatibility for Mac OS X 10.6

10.10 SDK compatibility for Mac OS X 10.6.

Both an SDK check and a runtime OS version check need to guard the use
of task_dyld_info_data_t::all_image_info_format. The SDK check, which
was already present, ensures that the field and macro constants are
present in the SDK. The runtime check is also necessary. This bug was
exposed in a 10.10 SDK and 10.6 deployment target build.

TEST=crashpad_snapshot_test ProcessTypes.DyldImagesSelf
BUG=chromium:463170
R=erikchen@chromium.org, rsesek@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/a3e313ecd72571d12965a51f9bad40b70b967cbc

[Mark Mentovai, 2015-08-05 18:06:52]

mark@chromium.org changed reviewers:
+ rsesek@chromium.org

[erikchen, 2015-08-05 18:10:01]

erikchen@chromium.org changed reviewers:
+ erikchen@chromium.org

[erikchen, 2015-08-05 18:10:01]

lgtm

[Robert Sesek, 2015-08-05 19:27:14]

LGTM

[Mark Mentovai, 2015-08-05 19:58:15]

Committed patchset #1 (id:1) manually as
a3e313ecd72571d12965a51f9bad40b70b967cbc (presubmit successful).