Implement Permissions.query() and static PermissionStatus.

Source/modules/permissions/PermissionController.h

+// Copyright 2015 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 PermissionController_h
+#define PermissionController_h
+
+#include "core/frame/FrameDestructionObserver.h"
+#include "platform/Supplementable.h"
+
+namespace blink {
+
+class WebPermissionClient;
+
+class PermissionController final
+    : public WillBeHeapSupplement<LocalFrame>
+    , public FrameDestructionObserver {
+    WTF_MAKE_NONCOPYABLE(PermissionController);
+public:
+    virtual ~PermissionController();
+
+    static void provideTo(LocalFrame&, WebPermissionClient*);
+    static PermissionController* from(LocalFrame&);
+    static const char* supplementName();
+
+    WebPermissionClient* client() const;
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    PermissionController(LocalFrame&, WebPermissionClient*);
+
+    // Inherited from FrameDestructionObserver.
+    virtual void willDetachFrameHost() override;
+
+    WebPermissionClient* m_client;
+};
+
+} // namespace blink
+
+#endif // PermissionController_h