CompositorWorkerProxyClientImpl to CompositorProxy cross thread reference is using WeakMember

third_party/WebKit/Source/core/dom/CompositorProxyClient.h

 // Copyright 2016 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 CompositorProxyClient_h
 #define CompositorProxyClient_h
 
 #include "core/CoreExport.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class CompositorProxy;
 
-class CORE_EXPORT CompositorProxyClient
-    : public GarbageCollectedFinalized<CompositorProxyClient> {
+class CORE_EXPORT CompositorProxyClient : public GarbageCollectedMixin {
  public:
   virtual ~CompositorProxyClient(){};
   DEFINE_INLINE_VIRTUAL_TRACE() {}
 
   virtual void registerCompositorProxy(CompositorProxy*) = 0;
   // It is not guaranteed to receive an unregister call for every registered
   // proxy. In fact we only receive one when a proxy is explicitly
   // disconnected otherwise we rely on oilpan collection process to remove the
   // weak reference to the proxy.
   virtual void unregisterCompositorProxy(CompositorProxy*) = 0;
 };
 
 }  // namespace blink
 
 #endif  // CompositorProxyClient_h