Create ScopedTempDir, implement it on POSIX, and use it where appropriate.

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 196 matching lines @@
         'test/executable_path_mac.cc',
         'test/mac/dyld.h',
         'test/mac/mach_errors.cc',
         'test/mac/mach_errors.h',
         'test/mac/mach_multiprocess.cc',
         'test/mac/mach_multiprocess.h',
         'test/multiprocess.cc',
         'test/multiprocess.h',
         'test/multiprocess_exec.cc',
         'test/multiprocess_exec.h',
+        'test/scoped_temp_dir.cc',
+        'test/scoped_temp_dir.h',
+        'test/scoped_temp_dir_posix.cc',
       ],
       'conditions': [
         ['OS=="mac"', {
           'link_settings': {
             'libraries': [
               '$(SDKROOT)/usr/lib/libbsm.dylib',
             ],
           },
         }],
       ],
@@ skipping 51 matching lines @@
         'posix/process_info_test.cc',
         'posix/symbolic_constants_posix_test.cc',
         'stdlib/string_number_conversion_test.cc',
         'stdlib/strlcpy_test.cc',
         'stdlib/strnlen_test.cc',
         'synchronization/semaphore_test.cc',
         'test/executable_path_test.cc',
         'test/mac/mach_multiprocess_test.cc',
         'test/multiprocess_exec_test.cc',
         'test/multiprocess_test.cc',
+        'test/scoped_temp_dir_test.cc',
       ],
       'conditions': [
         ['OS=="mac"', {
           'link_settings': {
             'libraries': [
               '$(SDKROOT)/System/Library/Frameworks/Foundation.framework',
             ],
           },
         }],
       ],
     },
     {
       'target_name': 'util_test_multiprocess_exec_test_child',
       'type': 'executable',
       'sources': [
         'test/multiprocess_exec_test_child.cc',
       ],
     },
   ],
 }