Use task_t, thread_t, and exception_handler_t uniformly

util/test/mac/mach_multiprocess.cc

Index: util/test/mac/mach_multiprocess.cc
diff --git a/util/test/mac/mach_multiprocess.cc b/util/test/mac/mach_multiprocess.cc
index f41024e52861ca5f98adeccb33d9d8ec94622210..10fe15de3c7e625a9600d6546e6288abdc570167 100644
--- a/util/test/mac/mach_multiprocess.cc
+++ b/util/test/mac/mach_multiprocess.cc
@@ -115,7 +115,7 @@ mach_port_t MachMultiprocess::RemotePort() const {
   return info_->remote_port;
 }
 
-mach_port_t MachMultiprocess::ChildTask() const {
+task_t MachMultiprocess::ChildTask() const {
   EXPECT_NE(kMachPortNull, info_->child_task);
   return info_->child_task;
 }