CompositorWorkerProxyClientImpl to CompositorProxy cross thread reference is using WeakMember

third_party/WebKit/Source/core/dom/AnimationWorkletProxyClient.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 AnimationWorkletProxyClient_h
 #define AnimationWorkletProxyClient_h
 
 #include "core/CoreExport.h"
 #include "core/dom/CompositorProxyClient.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
-class CORE_EXPORT AnimationWorkletProxyClient : public CompositorProxyClient {
+class CORE_EXPORT AnimationWorkletProxyClient

[sof, 2017/03/29 05:51:05]

What role does this abstraction play? i.e., it's now a synonym for GCFinalized.

[keishi, 2017/03/30 08:34:14]

I think it's suppose to be an interface so it can be accessed from core/ or
modules/. AnimationWorkletProxyClientImpl is in web/ and
AnimationWorkletProxyClient is used in modules/. I don't think I can delete this
class without upsetting DEPS.

Changed to GarbageCollectedMixin.

+    : public GarbageCollectedFinalized<AnimationWorkletProxyClient> {
   WTF_MAKE_NONCOPYABLE(AnimationWorkletProxyClient);
 
  public:
   AnimationWorkletProxyClient() {}
+  virtual ~AnimationWorkletProxyClient() {}
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
 };
 
 }  // namespace blink
 
 #endif  // AnimationWorkletProxyClient_h