Remove left-overs of PushSubscription.curve25519dh

Source/modules/push_messaging/PushSubscription.cpp

 // Copyright 2014 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.
 
 #include "config.h"
 #include "modules/push_messaging/PushSubscription.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/V8ObjectBuilder.h"
@@ skipping 28 matching lines @@
 
 PushSubscription::~PushSubscription()
 {
 }
 
 KURL PushSubscription::endpoint() const
 {
     return m_endpoint;
 }
 
-PassRefPtr<DOMArrayBuffer> PushSubscription::curve25519dh() const
-{
-    return m_curve25519dh;
-}
-
 PassRefPtr<DOMArrayBuffer> PushSubscription::getKey(const AtomicString& name) const
 {
     if (name == "curve25519dh")
         return m_curve25519dh;
 
     return nullptr;
 }
 
 ScriptPromise PushSubscription::unsubscribe(ScriptState* scriptState)
 {
@@ skipping 17 matching lines @@
 
     return result.scriptValue();
 }
 
 DEFINE_TRACE(PushSubscription)
 {
     visitor->trace(m_serviceWorkerRegistration);
 }
 
 } // namespace blink