Add wrappers around getxattr() and setxattr().

util/util.gyp

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 24 matching lines @@
         'file/string_file_writer.cc',
         'file/string_file_writer.h',
         'mac/checked_mach_address_range.cc',
         'mac/checked_mach_address_range.h',
         'mac/launchd.h',
         'mac/launchd.mm',
         'mac/mac_util.cc',
         'mac/mac_util.h',
         'mac/service_management.cc',
         'mac/service_management.h',
+        'mac/xattr.cc',
+        'mac/xattr.h',
         'mach/child_port.defs',
         'mach/child_port_handshake.cc',
         'mach/child_port_handshake.h',
         'mach/child_port_server.cc',
         'mach/child_port_server.h',
         'mach/child_port_types.h',
         'mach/composite_mach_message_server.cc',
         'mach/composite_mach_message_server.h',
         'mach/exc_client_variants.cc',
         'mach/exc_client_variants.h',
@@ skipping 181 matching lines @@
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'file/string_file_writer_test.cc',
         'mac/checked_mach_address_range_test.cc',
         'mac/launchd_test.mm',
         'mac/mac_util_test.mm',
         'mac/service_management_test.mm',
+        'mac/xattr_test.cc',
         'mach/child_port_handshake_test.cc',
         'mach/child_port_server_test.cc',
         'mach/composite_mach_message_server_test.cc',
         'mach/exc_client_variants_test.cc',
         'mach/exc_server_variants_test.cc',
         'mach/exception_behaviors_test.cc',
         'mach/exception_ports_test.cc',
         'mach/mach_extensions_test.cc',
         'mach/mach_message_server_test.cc',
         'mach/mach_message_test.cc',
@@ skipping 37 matching lines @@
     },
     {
       'target_name': 'util_test_multiprocess_exec_test_child',
       'type': 'executable',
       'sources': [
         'test/multiprocess_exec_test_child.cc',
       ],
     },
   ],
 }