[v8 gc] Introduce a base class for all objects that can have pending activity

third_party/WebKit/Source/core/streams/ReadableStreamReader.h

 // 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.
 
 #ifndef ReadableStreamReader_h
 #define ReadableStreamReader_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseProperty.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/core/v8/ToV8.h"
+#include "bindings/core/v8/V8GCRoot.h"
 #include "core/CoreExport.h"
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/streams/ReadableStream.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class DOMException;
 class ExceptionState;
 class ExecutionContext;
 class ScriptState;
 
 // ReadableStreamReader corresponds to the same-name class in the Streams spec
 // https://streams.spec.whatwg.org/.
-class CORE_EXPORT ReadableStreamReader final : public GarbageCollectedFinalized<ReadableStreamReader>, public ScriptWrappable, public ContextLifecycleObserver {
+class CORE_EXPORT ReadableStreamReader final : public GarbageCollectedFinalized<ReadableStreamReader>, public ScriptWrappable, public ContextLifecycleObserver, public V8GCRoot {
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ReadableStreamReader);
 public:
     // The stream must not be locked to any ReadableStreamReader when called.
     ReadableStreamReader(ExecutionContext*, ReadableStream*);
 
     ScriptPromise closed(ScriptState*);
     bool isActive() const;
     ScriptPromise cancel(ScriptState*);
     ScriptPromise cancel(ScriptState*, ScriptValue reason);
@@ skipping 11 matching lines @@
 private:
     using ClosedPromise = ScriptPromiseProperty<Member<ReadableStreamReader>, ToV8UndefinedGenerator, Member<DOMException>>;
 
     const Member<ReadableStream> m_stream;
     Member<ClosedPromise> m_closed;
 };
 
 } // namespace blink
 
 #endif // ReadableStreamReader_h