Oilpan: make custom element microtask dispatching lazy sweep savvy.

Source/core/dom/custom/CustomElementMicrotaskRunQueue.h

 // Copyright 2014 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 CustomElementMicrotaskRunQueue_h
 #define CustomElementMicrotaskRunQueue_h
 
 #include "platform/heap/Handle.h"
 #include "wtf/RefCounted.h"
 #include "wtf/WeakPtr.h"
 
 namespace blink {
 
 class CustomElementSyncMicrotaskQueue;
 class CustomElementAsyncImportMicrotaskQueue;
 class CustomElementMicrotaskStep;
 class HTMLImportLoader;
 
 class CustomElementMicrotaskRunQueue : public RefCountedWillBeGarbageCollectedFinalized<CustomElementMicrotaskRunQueue> {
     DECLARE_EMPTY_DESTRUCTOR_WILL_BE_REMOVED(CustomElementMicrotaskRunQueue)
 public:
     static PassRefPtrWillBeRawPtr<CustomElementMicrotaskRunQueue> create() { return adoptRefWillBeNoop(new CustomElementMicrotaskRunQueue()); }
 
     void enqueue(HTMLImportLoader* parentLoader, PassOwnPtrWillBeRawPtr<CustomElementMicrotaskStep>, bool importIsSync);
     void requestDispatchIfNeeded();
     bool isEmpty() const;
 
+    // Must be promptly finalized to prevent unsafe dispatching.
+    EAGERLY_FINALIZE();
     DECLARE_TRACE();
 
 private:
     static void dispatchIfAlive(WeakPtr<CustomElementMicrotaskRunQueue> self);
 
     CustomElementMicrotaskRunQueue();
 
     void dispatch();
 
     WeakPtrFactory<CustomElementMicrotaskRunQueue> m_weakFactory;
     RefPtrWillBeMember<CustomElementSyncMicrotaskQueue> m_syncQueue;
     RefPtrWillBeMember<CustomElementAsyncImportMicrotaskQueue> m_asyncQueue;
     bool m_dispatchIsPending;
 };
 
 } // namespace blink
 
 #endif // CustomElementMicrotaskRunQueue_h