Add an iframe permissions= attribute for implementing permission delegation

third_party/WebKit/Source/core/html/HTMLIFrameElementPermissions.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSDstyle license that can be
+// found in the LICENSE file.
+
+#ifndef HTMLIFrameElementPermissions_h
+#define HTMLIFrameElementPermissions_h
+
+#include "core/CoreExport.h"
+#include "core/dom/DOMTokenList.h"
+#include "public/platform/modules/permissions/WebPermissionType.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+class CORE_EXPORT HTMLIFrameElementPermissions final : public DOMTokenList {
+public:
+    static HTMLIFrameElementPermissions* create(DOMTokenListObserver* observer = nullptr)
+    {
+        return new HTMLIFrameElementPermissions(observer);
+    }
+
+    ~HTMLIFrameElementPermissions() override;
+
+    Vector<WebPermissionType> parseDelegatedPermissions(String& invalidTokensErrorMessage) const;
+
+private:
+    explicit HTMLIFrameElementPermissions(DOMTokenListObserver*);
+    bool validateTokenValue(const AtomicString& tokenValue, ExceptionState&) const override;
+};
+
+} // namespace blink
+
+#endif