Don’t use using directives (“using namespace”) in tests

util/mac/service_management_test.mm

Index: util/mac/service_management_test.mm
diff --git a/util/mac/service_management_test.mm b/util/mac/service_management_test.mm
index 9ca2e15ae61df9fd0233108f1f6bb3b64456f29c..278272165113a8bb8731c0fdf7b460e3a52ab4c6 100644
--- a/util/mac/service_management_test.mm
+++ b/util/mac/service_management_test.mm
@@ -30,10 +30,10 @@
 #include "util/posix/process_util.h"
 #include "util/stdlib/objc.h"
 
+namespace crashpad {
+namespace test {
 namespace {
 
-using namespace crashpad;
-
 // Ensures that the process with the specified PID is running, identifying it by
 // requiring that its argv[argc - 1] compare equal to last_arg.
 void ExpectProcessIsRunning(pid_t pid, std::string& last_arg) {
@@ -156,3 +156,5 @@ TEST(ServiceManagement, SubmitRemoveJob) {
 }
 
 }  // namespace
+}  // namespace test
+}  // namespace crashpad