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

util/mach/symbolic_constants_mach_test.cc

Index: util/mach/symbolic_constants_mach_test.cc
diff --git a/util/mach/symbolic_constants_mach_test.cc b/util/mach/symbolic_constants_mach_test.cc
index 4bc17c814c82dfb695a923e20343d323f3a86ab2..0410f2e37333af342a0148eab19884d70fcfd25c 100644
--- a/util/mach/symbolic_constants_mach_test.cc
+++ b/util/mach/symbolic_constants_mach_test.cc
@@ -25,10 +25,10 @@
 
 #define NUL_TEST_DATA(string) { string, arraysize(string) - 1 }
 
+namespace crashpad {
+namespace test {
 namespace {
 
-using namespace crashpad;
-
 // Options to use for normal tests, those that don’t require kAllowOr.
 const StringToSymbolicConstantOptions kNormalOptions[] = {
     0,
@@ -1062,3 +1062,5 @@ TEST(SymbolicConstantsMach, StringToThreadStateFlavor) {
 }
 
 }  // namespace
+}  // namespace test
+}  // namespace crashpad