Enable SIGABRT handler for out-of-process handlers on OS X as well

Currently the SIGABRT handler on OS X doesn't get enabled for out-of-process
handlers. I can't find any justification for this in the initial implementation
other than it was written solely for iOS where we don't actually support
out-of-process handlers. My coworker wrote this patch and we've had it applied
locally for a while and it seems to work fine for us, it hasn't shipped in a
release yet but it's in our beta channel and we haven't seen any problems. It's
useful since it allows `kill -ABRT` for child processes to produce a minidump.

Mark: I reviewed this in bugzilla but can you give it a once-over?

[Mark Mentovai]

In Chrome, we do this

https://chromium.googlesource.com/chromium/src/+/00ea022b81af/components/cras...

so I don’t want to take this in the Mac Breakpad client until after Chrome moves
off of that and onto the Crashpad/bpoop client. Can this wait a couple of weeks?

[Ted Mielczarek]

On 2014/10/24 12:45:44, Mark Mentovai wrote:
> In Chrome, we do this
> 
>
https://chromium.googlesource.com/chromium/src/+/00ea022b81af/components/cras...
> 
> so I don’t want to take this in the Mac Breakpad client until after Chrome
moves
> off of that and onto the Crashpad/bpoop client. Can this wait a couple of
weeks?

Sure, we've had this as a local patch for a few months now, it won't hurt
anything to wait a bit longer.

[Ted Mielczarek]

On 2014/10/24 15:03:37, Ted Mielczarek wrote:
> On 2014/10/24 12:45:44, Mark Mentovai wrote:
> > In Chrome, we do this
> > 
> >
>
https://chromium.googlesource.com/chromium/src/+/00ea022b81af/components/cras...
> > 
> > so I don’t want to take this in the Mac Breakpad client until after Chrome
> moves
> > off of that and onto the Crashpad/bpoop client. Can this wait a couple of
> weeks?
> 
> Sure, we've had this as a local patch for a few months now, it won't hurt
> anything to wait a bit longer.

I know you consider the Mac client dead code now, but do you mind if I land
this? I'd like to get rid of our local patches (again).

[Mark Mentovai]

LGTM. I didn’t really think the code change through very carefully, but I’m not
using this code anymore, and if it makes things easier for you, that’s a
benefit.

I also encourage you to look at integrating the Crashpad client for Mac too. It
may suit your needs well (and if not, I’d be interested in knowing what about it
is unappealing).