bluetooth: readValue Blink implementation

Source/modules/bluetooth/BluetoothGATTCharacteristic.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 BluetoothGATTCharacteristic_h
 #define BluetoothGATTCharacteristic_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/bluetooth/WebBluetoothGATTCharacteristic.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
+class ScriptPromise;
 class ScriptPromiseResolver;
+class ScriptState;
 
 // BluetoothGATTCharacteristic represents a GATT Characteristic, which is a
 // basic data element that provides further information about a peripheral's
 // service.
 //
 // Callbacks providing WebBluetoothGATTCharacteristic objects are handled by
 // CallbackPromiseAdapter templatized with this class. See this class's
 // "Interface required by CallbackPromiseAdapter" section and the
 // CallbackPromiseAdapter class comments.
 class BluetoothGATTCharacteristic final
     : public GarbageCollectedFinalized<BluetoothGATTCharacteristic>
     , public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     explicit BluetoothGATTCharacteristic(PassOwnPtr<WebBluetoothGATTCharacteristic>);
 
     // Interface required by CallbackPromiseAdapter.
     typedef WebBluetoothGATTCharacteristic WebType;
     static BluetoothGATTCharacteristic* take(ScriptPromiseResolver* , WebBluetoothGATTCharacteristic*);
     static void dispose(WebBluetoothGATTCharacteristic*);
 
     // Interface required by garbage collection.
     DEFINE_INLINE_TRACE() { }
 
     // IDL exposed interface:
     String uuid() { return m_webCharacteristic->uuid; }
+    ScriptPromise readValue(ScriptState*);
 
 private:
     OwnPtr<WebBluetoothGATTCharacteristic> m_webCharacteristic;
 };
 
 } // namespace blink
 
 #endif // BluetoothGATTCharacteristic_h