Make base::Optional trivially destructible when possible.

base/template_util_unittest.cc

Index: base/template_util_unittest.cc
diff --git a/base/template_util_unittest.cc b/base/template_util_unittest.cc
index 5686d7c752d04c04771b0ee741984490de5778cc..f0f833686ee2cf9bdcd1df5ff2e52083d30c6a75 100644
--- a/base/template_util_unittest.cc
+++ b/base/template_util_unittest.cc
@@ -48,5 +48,19 @@ static_assert(is_move_assignable<AssignCopy>::value, "IsMoveAssignable");
 static_assert(is_move_assignable<AssignNoCopy>::value, "IsMoveAssignable");
 static_assert(!is_move_assignable<AssignNoMove>::value, "IsMoveAssignable");
 
+struct TriviallyDestructible {
+  int field;
+};
+
+class NonTriviallyDestructible {
+  ~NonTriviallyDestructible() {}
+};
+
+static_assert(is_trivially_destructible<int>::value, "IsTriviallyDestructible");
+static_assert(is_trivially_destructible<TriviallyDestructible>::value,
+              "IsTriviallyDestructible");
+static_assert(!is_trivially_destructible<NonTriviallyDestructible>::value,
+              "IsTriviallyDestructible");
+
 }  // namespace
 }  // namespace base