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

util/stdlib/string_number_conversion_test.cc

Index: util/stdlib/string_number_conversion_test.cc
diff --git a/util/stdlib/string_number_conversion_test.cc b/util/stdlib/string_number_conversion_test.cc
index ef1376c76700dce3595cdbfeca728d7f9780a4d7..ec0d44ae301dd267381923ce819a03649279d751 100644
--- a/util/stdlib/string_number_conversion_test.cc
+++ b/util/stdlib/string_number_conversion_test.cc
@@ -19,10 +19,10 @@
 
 #include <limits>
 
+namespace crashpad {
+namespace test {
 namespace {
 
-using namespace crashpad;
-
 TEST(StringNumberConversion, StringToInt) {
   const struct {
     const char* string;
@@ -216,3 +216,5 @@ TEST(StringNumberConversion, StringToUnsignedInt) {
 }
 
 }  // namespace
+}  // namespace test
+}  // namespace crashpad