[ES6 modules] Introduce Modulator "module map settings object"

third_party/WebKit/Source/core/dom/Modulator.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 Modulator_h
+#define Modulator_h
+
+#include "core/CoreExport.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class LocalFrame;
+
+// A Modulator is an interface for "environment settings object" concept for
+// module scripts.
+// https://html.spec.whatwg.org/#environment-settings-object
+//
+// A Modulator also serves as an entry point for various module spec algorithms.
+class CORE_EXPORT Modulator : public GarbageCollectedMixin {
+ public:
+  static Modulator* from(LocalFrame*);
+};
+
+}  // namespace blink
+
+#endif