Make base::Value::TYPE a scoped enum.

base/json/json_value_serializer_unittest.cc

Index: base/json/json_value_serializer_unittest.cc
diff --git a/base/json/json_value_serializer_unittest.cc b/base/json/json_value_serializer_unittest.cc
index 43ddc9c4574cd63b5d5a3a2fb8523a3986ef5079..e835700a1a5faeb91139c75f3d280c42b3b460b6 100644
--- a/base/json/json_value_serializer_unittest.cc
+++ b/base/json/json_value_serializer_unittest.cc
@@ -224,7 +224,7 @@ TEST(JSONValueSerializerTest, Roundtrip) {
   Value* null_value = nullptr;
   ASSERT_TRUE(root_dict->Get("null", &null_value));
   ASSERT_TRUE(null_value);
-  ASSERT_TRUE(null_value->IsType(Value::TYPE_NULL));
+  ASSERT_TRUE(null_value->IsType(Value::Type::NONE));
 
   bool bool_value = false;
   ASSERT_TRUE(root_dict->GetBoolean("bool", &bool_value));
@@ -417,7 +417,7 @@ TEST_F(JSONFileValueSerializerTest, Roundtrip) {
   Value* null_value = nullptr;
   ASSERT_TRUE(root_dict->Get("null", &null_value));
   ASSERT_TRUE(null_value);
-  ASSERT_TRUE(null_value->IsType(Value::TYPE_NULL));
+  ASSERT_TRUE(null_value->IsType(Value::Type::NONE));
 
   bool bool_value = false;
   ASSERT_TRUE(root_dict->GetBoolean("bool", &bool_value));