Explicitly CHECK arguments in dbus::MessageWriter::AppendString/ObjectPath

dbus/dbus.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 16 matching lines @@
         'file_descriptor.h',
         'message.cc',
         'message.h',
         'object_path.cc',
         'object_path.h',
         'object_proxy.cc',
         'object_proxy.h',
         'property.cc',
         'property.h',
         'scoped_dbus_error.h',
+        'string_util.cc',
+        'string_util.h',
         'values_util.cc',
         'values_util.h',
       ],
     },
     {
       # Protobuf compiler / generator test protocol buffer
       'target_name': 'dbus_test_proto',
       'type': 'static_library',
       'sources': [ 'test_proto.proto' ],
       'variables': {
@@ skipping 36 matching lines @@
         'dbus_test_proto',
         'dbus_test_support',
       ],
       'sources': [
         'bus_unittest.cc',
         'end_to_end_async_unittest.cc',
         'end_to_end_sync_unittest.cc',
         'message_unittest.cc',
         'mock_unittest.cc',
         'property_unittest.cc',
+        'string_util_unittest.cc',
         'test_service.cc',
         'test_service.h',
         'values_util_unittest.cc',
       ],
       'include_dirs': [
         '..',
       ],
     },
   ],
 }