Oilpan: Replace EAGERLY_FINALIZE in EventTarget's hierarchy with pre-finalizers

third_party/WebKit/Source/modules/webmidi/MIDIAccess.cpp

 /*
  * 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 36 matching lines @@
 
 using PortState = MIDIAccessor::MIDIPortState;
 
 MIDIAccess::MIDIAccess(PassOwnPtr<MIDIAccessor> accessor, bool sysexEnabled, const Vector<MIDIAccessInitializer::PortDescriptor>& ports, ExecutionContext* executionContext)
     : ActiveScriptWrappable(this)
     , ActiveDOMObject(executionContext)
     , m_accessor(accessor)
     , m_sysexEnabled(sysexEnabled)
     , m_hasPendingActivity(false)
 {
+    ThreadState::current()->registerPreFinalizer(this);
     m_accessor->setClient(this);
     for (size_t i = 0; i < ports.size(); ++i) {
         const MIDIAccessInitializer::PortDescriptor& port = ports[i];
         if (port.type == MIDIPort::TypeInput) {
             m_inputs.append(MIDIInput::create(this, port.id, port.manufacturer, port.name, port.version, port.state));
         } else {
             m_outputs.append(MIDIOutput::create(this, m_outputs.size(), port.id, port.manufacturer, port.name, port.version, port.state));
         }
     }
 }
 
 MIDIAccess::~MIDIAccess()
 {
 }
 
+void MIDIAccess::dispose()
+{
+    m_accessor.clear();
+}
+
 EventListener* MIDIAccess::onstatechange()
 {
     return getAttributeEventListener(EventTypeNames::statechange);
 }
 
 void MIDIAccess::setOnstatechange(RawPtr<EventListener> listener)
 {
     m_hasPendingActivity = listener;
     setAttributeEventListener(EventTypeNames::statechange, listener);
 }
@@ skipping 120 matching lines @@
 
 DEFINE_TRACE(MIDIAccess)
 {
     visitor->trace(m_inputs);
     visitor->trace(m_outputs);
     RefCountedGarbageCollectedEventTargetWithInlineData<MIDIAccess>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink