Make CrashAwareSleep more accurate on POSIX (checking if the process exists).

Make CrashAwareSleep more accurate on POSIX (checking if the process exists).

[Mark Mentovai, 2009-03-05 15:51:34]

I don't see any functional difference here other than being able to
DCHECK(waitpid_success).

Seems like it might be easier to just DCHECK ret_pid in WaitpidWithTimeout and
not have to touch its parameter list or its callers.

What are we trying to solve here?  Are we calling waitpid for children that
don't exist?  Is waitpid being interrupted by a signal?  Are there just random
failures that you think this DCHECK will help us figure out?  (errno might be
helpful.)

[Mark Mentovai, 2009-03-05 15:56:27]

http://codereview.chromium.org/39185/diff/1/2
File base/process_util_posix.cc (right):

http://codereview.chromium.org/39185/diff/1/2#newcode261
Line 261: return waitpid_success;
Oh, never mind my previous comment about functional equivalence to the original
version, I missed that you changed this line from "return true;".

lgtm.

[agl, 2009-03-05 21:23:11]

LGTM

http://codereview.chromium.org/39185/diff/1/2
File base/process_util_posix.cc (right):

http://codereview.chromium.org/39185/diff/1/2#newcode234
Line 234: *success = (ret_pid != -1);
outputs at the end of the argument list are generally optional, so you should
wrap this in "if (success) ..."