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

third_party/WebKit/Source/modules/webmidi/MIDIPort.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef MIDIPort_h
 #define MIDIPort_h
 
 #include "bindings/core/v8/ScriptPromise.h"
+#include "bindings/core/v8/V8GCRoot.h"
 #include "core/dom/ActiveDOMObject.h"
 #include "core/dom/ExceptionCode.h"
 #include "modules/EventTargetModules.h"
 #include "modules/webmidi/MIDIAccessor.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class MIDIAccess;
 
-class MIDIPort : public RefCountedGarbageCollectedEventTargetWithInlineData<MIDIPort>, public ActiveDOMObject {
+class MIDIPort : public RefCountedGarbageCollectedEventTargetWithInlineData<MIDIPort>, public ActiveDOMObject, public V8GCRoot {
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(MIDIPort);
     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MIDIPort);
 public:
     enum ConnectionState {
         ConnectionStateOpen,
         ConnectionStateClosed,
         ConnectionStatePending
     };
 
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     TypeCode m_type;
     String m_version;
     Member<MIDIAccess> m_access;
     MIDIAccessor::MIDIPortState m_state;
     ConnectionState m_connection;
 };
 
 } // namespace blink
 
 #endif // MIDIPort_h