[inspector_protocol] Allow custom json parser.

lib/DispatcherBase_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 "DispatcherBase.h"
 //#include "Parser.h"
 
 {% for namespace in config.protocol.namespace %}
 namespace {{namespace}} {
 {% endfor %}
@@ skipping 70 matching lines @@
     : m_frontendChannel(frontendChannel) { }
 
 DispatcherBase::~DispatcherBase()
 {
     clearFrontend();
 }
 
 // static
 bool DispatcherBase::getCommandName(const String& message, String* result)
 {
-    std::unique_ptr<protocol::Value> value = parseJSON(message);
+    std::unique_ptr<protocol::Value> value = StringUtil::parseJSON(message);
     if (!value)
         return false;
 
     protocol::DictionaryValue* object = DictionaryValue::cast(value.get());
     if (!object)
         return false;
 
     if (!object->getString("method", result))
         return false;
 
@@ skipping 114 matching lines @@
         return DispatchResponse::kError;
     }
     return it->second->dispatch(callId, method, std::move(messageObject));
 }
 
 UberDispatcher::~UberDispatcher() = default;
 
 {% for namespace in config.protocol.namespace %}
 } // namespace {{namespace}}
 {% endfor %}