Attach a WebBluetooth to the LocalFrame and use it if it's available.

Source/modules/bluetooth/BluetoothSupplement.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 BluetoothSupplement_h
+#define BluetoothSupplement_h
+
+#include "core/frame/LocalFrame.h"
+
+namespace blink {
+
+class WebBluetooth;
+
+// This class is attached to a LocalFrame in WebLocalFrameImpl::setCoreFrame, to
+// pass WebFrameClient::bluetooth() (accessible by web/ only) to the Bluetooth
+// code in modules/.
+class BLINK_EXPORT BluetoothSupplement : public NoBaseWillBeGarbageCollected<BluetoothSupplement>, public WillBeHeapSupplement<LocalFrame> {
+    WTF_MAKE_NONCOPYABLE(BluetoothSupplement);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(BluetoothSupplement);
+
+public:
+    static const char* supplementName();
+
+    static void provideTo(LocalFrame&, WebBluetooth*);
+
+    // Returns the WebBluetooth attached to the ScriptState's frame if that exists;
+    // otherwise the Platform's WebBluetooth.
+    static WebBluetooth* from(ScriptState*);
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    explicit BluetoothSupplement(WebBluetooth*);
+
+    WebBluetooth* m_bluetooth;
+};
+
+} // namespace blink
+
+#endif // BluetoothRoutingId_h