[iOS/OS X] Allow base::scoped_nsobject<> to be used when ARC is enabled.

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 299 matching lines @@
           'mac/mach_port_broker.mm',
           'mac/mach_port_util.cc',
           'mac/mach_port_util.h',
           'mac/objc_property_releaser.h',
           'mac/objc_property_releaser.mm',
           'mac/os_crash_dumps.cc',
           'mac/os_crash_dumps.h',
           'mac/scoped_aedesc.h',
           'mac/scoped_authorizationref.h',
           'mac/scoped_block.h',
+          'mac/scoped_block.mm',
           'mac/scoped_cftyperef.h',
           'mac/scoped_ioobject.h',
           'mac/scoped_ioplugininterface.h',
           'mac/scoped_launch_data.h',
           'mac/scoped_mach_port.cc',
           'mac/scoped_mach_port.h',
           'mac/scoped_mach_vm.cc',
           'mac/scoped_mach_vm.h',
           'mac/scoped_nsautorelease_pool.h',
           'mac/scoped_nsautorelease_pool.mm',
           'mac/scoped_nsobject.h',
+          'mac/scoped_nsobject.mm',
           'mac/scoped_objc_class_swizzler.h',
           'mac/scoped_objc_class_swizzler.mm',
           'mac/scoped_sending_event.h',
           'mac/scoped_sending_event.mm',
           'mac/scoped_typeref.h',
           'mac/sdk_forward_declarations.h',
           'mac/sdk_forward_declarations.mm',
           'macros.h',
           'md5.cc',
           'md5.h',
@@ skipping 741 matching lines @@
           'i18n/time_formatting.h',
           'i18n/timezone.cc',
           'i18n/timezone.h',
           'i18n/utf8_validator_tables.cc',
           'i18n/utf8_validator_tables.h',
         ],
       }]
     ],
   },
 }