Use base/time/time_posix.cc on OS X and iOS.

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 674 matching lines @@
           'time/clock.cc',
           'time/clock.h',
           'time/default_clock.cc',
           'time/default_clock.h',
           'time/default_tick_clock.cc',
           'time/default_tick_clock.h',
           'time/tick_clock.cc',
           'time/tick_clock.h',
           'time/time.cc',
           'time/time.h',
-          'time/time_mac.cc',
           'time/time_posix.cc',
           'time/time_win.cc',
           'timer/elapsed_timer.cc',
           'timer/elapsed_timer.h',
           'timer/hi_res_timer_manager.h',
           'timer/hi_res_timer_manager_posix.cc',
           'timer/hi_res_timer_manager_win.cc',
           'timer/mock_timer.cc',
           'timer/mock_timer.h',
           'timer/timer.cc',
@@ skipping 348 matching lines @@
           'i18n/time_formatting.h',
           'i18n/timezone.cc',
           'i18n/timezone.h',
           'i18n/utf8_validator_tables.cc',
           'i18n/utf8_validator_tables.h',
         ],
       }]
     ],
   },
 }