json_schema_compiler: Don't use deprecated ListValue::Append(Value*) overload.

tools/json_schema_compiler/test/additional_properties_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/json_schema_compiler/test/additional_properties.h"
 
 #include <memory>
 #include <utility>
 
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 26 matching lines @@
   }
 }
 
 TEST(JsonSchemaCompilerAdditionalPropertiesTest,
     AdditionalPropertiesParamsCreate) {
   std::unique_ptr<base::DictionaryValue> param_object_value(
       new base::DictionaryValue());
   param_object_value->SetString("str", "a");
   param_object_value->SetInteger("num", 1);
   std::unique_ptr<base::ListValue> params_value(new base::ListValue());
-  params_value->Append(param_object_value->DeepCopy());
+  params_value->Append(param_object_value->CreateDeepCopy());
   std::unique_ptr<AdditionalProperties::Params> params(
       AdditionalProperties::Params::Create(*params_value));
   EXPECT_TRUE(params.get());
   EXPECT_TRUE(params->param_object.additional_properties.Equals(
       param_object_value.get()));
 }
 
 TEST(JsonSchemaCompilerAdditionalPropertiesTest,
     ReturnAdditionalPropertiesResultCreate) {
   ReturnAdditionalProperties::Results::ResultObject result_object;
   result_object.integer = 5;
   result_object.additional_properties["key"] = "value";
 
   base::ListValue expected;
   {
     std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue());
     dict->SetInteger("integer", 5);
     dict->SetString("key", "value");
     expected.Append(std::move(dict));
   }
 
   EXPECT_TRUE(base::Value::Equals(
       ReturnAdditionalProperties::Results::Create(result_object).get(),
       &expected));
 }