Tidy up CompositorWorkerManager unit tests.

Source/modules/compositorworker/CompositorWorkerMessagingProxy.cpp

 // 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.
 
 #include "config.h"
 #include "modules/compositorworker/CompositorWorkerMessagingProxy.h"
 
 #include "core/workers/WorkerThreadStartupData.h"
 #include "modules/compositorworker/CompositorWorkerThread.h"
 
 namespace blink {
 
-CompositorWorkerMessagingProxy::CompositorWorkerMessagingProxy(InProcessWorkerBase* worker, PassOwnPtrWillBeRawPtr<WorkerClients> workerClients)
-    : WorkerMessagingProxy(worker, workerClients)
+CompositorWorkerMessagingProxy::CompositorWorkerMessagingProxy(InProcessWorkerBase* worker)
+    : WorkerMessagingProxy(worker, nullptr)
 {
 }
 
 CompositorWorkerMessagingProxy::~CompositorWorkerMessagingProxy()
 {
 }
 
 PassRefPtr<WorkerThread> CompositorWorkerMessagingProxy::createWorkerThread(double originTime)
 {
     return CompositorWorkerThread::create(loaderProxy(), workerObjectProxy(), originTime);
 }
 
 } // namespace blink