Specify system framework dependencies properly in .gyp files

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,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 {
   'targets': [
     {
       'target_name': 'util',
       'type': 'static_library',
       'dependencies': [
         '../compat/compat.gyp:compat',
         '../third_party/mini_chromium/mini_chromium/base/base.gyp:base',
       ],
       'include_dirs': [
         '..',
         '<(INTERMEDIATE_DIR)',
       ],
+      'link_settings': {
+        'libraries': [
+          '$(SDKROOT)/System/Library/Frameworks/CoreFoundation.framework',
+          '$(SDKROOT)/System/Library/Frameworks/Foundation.framework',
+          '$(SDKROOT)/System/Library/Frameworks/IOKit.framework',
+        ],
+      },
       'sources': [
         'file/fd_io.cc',
         'file/fd_io.h',
         'file/file_writer.cc',
         'file/file_writer.h',
         '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',
@@ skipping 187 matching lines @@
     },
     {
       'target_name': 'util_test_multiprocess_exec_test_child',
       'type': 'executable',
       'sources': [
         'test/multiprocess_exec_test_child.cc',
       ],
     },
   ],
 }