Add WebUSB bindings and client interface [part 1]

Source/modules/webusb/USBController.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 USBController_h
+#define USBController_h
+
+#include "core/frame/LocalFrame.h"
+#include "core/frame/LocalFrameLifecycleObserver.h"
+#include "modules/ModulesExport.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class WebUSBClient;
+
+class MODULES_EXPORT USBController final
+    : public NoBaseWillBeGarbageCollectedFinalized<USBController>
+    , public WillBeHeapSupplement<LocalFrame>
+    , public LocalFrameLifecycleObserver {
+    WTF_MAKE_NONCOPYABLE(USBController);
+public:
+    virtual ~USBController();
+
+    WebUSBClient* client() { return m_client; }
+
+    static void provideTo(LocalFrame&, WebUSBClient*);
+    static USBController& from(LocalFrame&);
+    static const char* supplementName();
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    USBController(LocalFrame&, WebUSBClient*);
+
+    // Inherited from LocalFrameLifecycleObserver.
+    void willDetachFrameHost() override;
+
+    WebUSBClient* m_client;
+};
+
+} // namespace blink
+
+#endif // USBController_h