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

util/mach/task_memory_test.cc

Index: util/mach/task_memory_test.cc
diff --git a/util/mach/task_memory_test.cc b/util/mach/task_memory_test.cc
index 3ee813abb3d9b9eec6c488bd91b8558f1b302c4c..523e95a591fd9250a89a7faae11eaf46883e4038 100644
--- a/util/mach/task_memory_test.cc
+++ b/util/mach/task_memory_test.cc
@@ -26,11 +26,10 @@
 #include "gtest/gtest.h"
 #include "util/test/mac/mach_errors.h"
 
+namespace crashpad {
+namespace test {
 namespace {
 
-using namespace crashpad;
-using namespace crashpad::test;
-
 TEST(TaskMemory, ReadSelf) {
   vm_address_t address = 0;
   const vm_size_t kSize = 4 * PAGE_SIZE;
@@ -552,3 +551,5 @@ TEST(TaskMemory, MappedMemoryReadCString) {
 }
 
 }  // namespace
+}  // namespace test
+}  // namespace crashpad