Introduce AnimationWorkletProxyClient and necessary plumbing to get it in worklet messaging proxy.

third_party/WebKit/Source/modules/compositorworker/CompositorWorker.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 "modules/compositorworker/CompositorWorker.h"
 
 #include "bindings/core/v8/ExceptionState.h"
-#include "core/dom/CompositorProxyClient.h"
+#include "core/dom/CompositorProxyClientFactory.h"
+#include "core/dom/CompositorWorkerProxyClient.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/frame/LocalFrame.h"
 #include "core/page/ChromeClient.h"
 #include "core/workers/WorkerClients.h"
 #include "modules/EventTargetModules.h"
 #include "modules/compositorworker/CompositorWorkerMessagingProxy.h"
 #include "modules/compositorworker/CompositorWorkerThread.h"
 
 namespace blink {
@@ skipping 29 matching lines @@
 
 const AtomicString& CompositorWorker::interfaceName() const {
   return EventTargetNames::CompositorWorker;
 }
 
 InProcessWorkerMessagingProxy*
 CompositorWorker::createInProcessWorkerMessagingProxy(
     ExecutionContext* context) {
   Document* document = toDocument(context);
   WorkerClients* workerClients = WorkerClients::create();
-  provideCompositorProxyClientTo(
-      workerClients,
-      document->frame()->chromeClient().createCompositorProxyClient(
-          document->frame()));
+  CompositorWorkerProxyClient* client =
+      static_cast<CompositorWorkerProxyClient*>(
+          document->frame()
+              ->chromeClient()
+              .compositorProxyClientFactory(document->frame())
+              ->create(CompositorProxyClient::kWorkerClient));
+  provideCompositorWorkerProxyClientTo(workerClients, client);
   return new CompositorWorkerMessagingProxy(this, workerClients);
 }
 
 }  // namespace blink