Add ScopedTaskSuspend and its test

util/util.gyp

Index: util/util.gyp
diff --git a/util/util.gyp b/util/util.gyp
index 80df85843be58121edffb4dd2a4e60906aa14faa..6433a524f371a23a54f658069af40018fcd3b005 100644
--- a/util/util.gyp
+++ b/util/util.gyp
@@ -71,6 +71,8 @@
         'mach/mach_extensions.h',
         'mach/mach_message_server.cc',
         'mach/mach_message_server.h',
+        'mach/scoped_task_suspend.cc',
+        'mach/scoped_task_suspend.h',
         'mach/symbolic_constants_mach.cc',
         'mach/symbolic_constants_mach.h',
         'mach/task_memory.cc',
@@ -92,6 +94,8 @@
         'numeric/safe_assignment.h',
         'posix/process_util.h',
         'posix/process_util_mac.cc',
+        'posix/scoped_fcntl_flags.cc',
+        'posix/scoped_fcntl_flags.h',
         'posix/symbolic_constants_posix.cc',
         'posix/symbolic_constants_posix.h',
         'stdlib/cxx.h',
@@ -225,6 +229,7 @@
         'mach/exception_ports_test.cc',
         'mach/mach_extensions_test.cc',
         'mach/mach_message_server_test.cc',
+        'mach/scoped_task_suspend_test.cc',
         'mach/symbolic_constants_mach_test.cc',
         'mach/task_memory_test.cc',
         'misc/clock_test.cc',
@@ -236,6 +241,7 @@
         'numeric/in_range_cast_test.cc',
         'numeric/int128_test.cc',
         'posix/process_util_test.cc',
+        'posix/scoped_fcntl_flags_test.cc',
         'posix/symbolic_constants_posix_test.cc',
         'stdlib/string_number_conversion_test.cc',
         'stdlib/strlcpy_test.cc',