Define the Settings interface for a CrashReportDatabase and provide a Mac implementation.

client/client.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 18 matching lines @@
         'capture_context_mac.S',
         'capture_context_mac.h',
         'crash_report_database.cc',
         'crash_report_database.h',
         'crash_report_database_mac.mm',
         'crash_report_database_win.cc',
         'crashpad_client.h',
         'crashpad_client_mac.cc',
         'crashpad_info.cc',
         'crashpad_info.h',
+        'settings.h',
+        'settings_mac.h',
+        'settings_mac.mm',
         'simple_string_dictionary.cc',
         'simple_string_dictionary.h',
         'simulate_crash.h',
         'simulate_crash_mac.cc',
         'simulate_crash_mac.h',
       ],
       'conditions': [
         ['OS=="win"', {
           'link_settings': {
             'libraries': [
@@ skipping 14 matching lines @@
         '../third_party/mini_chromium/mini_chromium/base/base.gyp:base',
         '../util/util.gyp:util',
         '../util/util.gyp:util_test_lib',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'capture_context_mac_test.cc',
         'crash_report_database_test.cc',
+        'settings_test.cc',
         'simple_string_dictionary_test.cc',
         'simulate_crash_mac_test.cc',
       ],
+      'conditions': [
+        ['OS=="win"', {
+          'sources!' [
+            # There is no settings_win.cc file yet to make this test pass.
+            'settings_test.cc',
+          ],
+        }],
+      ],
     },
   ],
 }