Run NonThreadSafeDeathTests in the threadsafe gtest mode.

base/threading/non_thread_safe_unittest.cc

Index: base/threading/non_thread_safe_unittest.cc
diff --git a/base/threading/non_thread_safe_unittest.cc b/base/threading/non_thread_safe_unittest.cc
index 7776228f2f29a99c509c11db0ee496b0f69c1fd5..89d48a09458c6d67367a747f8ab61e15adc2d6a6 100644
--- a/base/threading/non_thread_safe_unittest.cc
+++ b/base/threading/non_thread_safe_unittest.cc
@@ -113,6 +113,7 @@ void NonThreadSafeClass::MethodOnDifferentThreadImpl() {
 
 #if DCHECK_IS_ON()
 TEST(NonThreadSafeDeathTest, MethodNotAllowedOnDifferentThreadInDebug) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
   ASSERT_DCHECK_DEATH({ NonThreadSafeClass::MethodOnDifferentThreadImpl(); });
 }
 #else
@@ -136,6 +137,7 @@ void NonThreadSafeClass::DestructorOnDifferentThreadImpl() {
 
 #if DCHECK_IS_ON()
 TEST(NonThreadSafeDeathTest, DestructorNotAllowedOnDifferentThreadInDebug) {
+  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
   ASSERT_DCHECK_DEATH(
       { NonThreadSafeClass::DestructorOnDifferentThreadImpl(); });
 }