[inspector_protocol] Allow custom json parser.

lib/Object_cpp.template

 // Copyright 2016 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 "Object.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
 
 std::unique_ptr<Object> Object::parse(protocol::Value* value, ErrorSupport* errors)
 {
-    protocol::DictionaryValue* object = DictionaryValue::cast(value);
-    if (!object) {
+    protocol::DictionaryValue* dictionary = DictionaryValue::cast(value);
+    if (!dictionary) {
         errors->addError("object expected");
         return nullptr;
     }
-    return wrapUnique(new Object(wrapUnique(static_cast<DictionaryValue*>(object->clone().release()))));
+    dictionary = static_cast<protocol::DictionaryValue*>(dictionary->clone().release());
+    return std::unique_ptr<Object>(new Object(std::unique_ptr<DictionaryValue>(dictionary)));
 }
 
 std::unique_ptr<protocol::DictionaryValue> Object::serialize() const
 {
     return DictionaryValue::cast(m_object->clone());
 }
 
 std::unique_ptr<Object> Object::clone() const
 {
-    return wrapUnique(new Object(DictionaryValue::cast(m_object->clone())));
+    return std::unique_ptr<Object>(new Object(DictionaryValue::cast(m_object->clone())));
 }
 
 Object::Object(std::unique_ptr<protocol::DictionaryValue> object) : m_object(std::move(object)) { }
 
 Object::~Object() { }
 
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}