[ES6 modules] Introduce ModuleScript model object

third_party/WebKit/Source/bindings/core/v8/ScriptModule.h

 // Copyright 2017 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.
 
 #ifndef ScriptModule_h
 #define ScriptModule_h
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/SharedPersistent.h"
 #include "core/CoreExport.h"
 #include "wtf/Allocator.h"
 #include "wtf/text/WTFString.h"
 #include <v8.h>
 
 namespace blink {
 
 class CORE_EXPORT ScriptModule final {
   DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
 
  public:
   static ScriptModule compile(v8::Isolate*,
                               const String& source,
                               const String& fileName);
 
+  ScriptModule() {}
   ScriptModule(const ScriptModule& module) : m_module(module.m_module) {}
   ~ScriptModule();
 
   bool instantiate(ScriptState*);
   void evaluate(ScriptState*);
 
   bool isNull() const { return m_module->isEmpty(); }
 
  private:
   ScriptModule(v8::Isolate*, v8::Local<v8::Module>);
 
   RefPtr<SharedPersistent<v8::Module>> m_module;
 };
 
 }  // namespace blink
 
 #endif  // ScriptModule_h