Add support for backgrounding processes on the Mac

base/base.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'includes': [
     'trace_event/trace_event.gypi',
   ],
   'target_defaults': {
     'variables': {
@@ skipping 458 matching lines @@
           'process/process_info_mac.cc',
           'process/process_info_win.cc',
           'process/process_iterator.cc',
           'process/process_iterator.h',
           'process/process_iterator_freebsd.cc',
           'process/process_iterator_linux.cc',
           'process/process_iterator_mac.cc',
           'process/process_iterator_openbsd.cc',
           'process/process_iterator_win.cc',
           'process/process_linux.cc',
+          'process/process_mac.cc',
           'process/process_metrics.cc',
           'process/process_metrics.h',
           'process/process_metrics_freebsd.cc',
           'process/process_metrics_ios.cc',
           'process/process_metrics_linux.cc',
           'process/process_metrics_mac.cc',
           'process/process_metrics_openbsd.cc',
           'process/process_metrics_posix.cc',
           'process/process_metrics_win.cc',
           'process/process_posix.cc',
@@ skipping 525 matching lines @@
           'i18n/time_formatting.h',
           'i18n/timezone.cc',
           'i18n/timezone.h',
           'i18n/utf8_validator_tables.cc',
           'i18n/utf8_validator_tables.h',
         ],
       }]
     ],
   },
 }