Oilpan: prevent player from accessing its media element during finalization

Source/core/html/HTMLMediaElement.h

Index: Source/core/html/HTMLMediaElement.h
diff --git a/Source/core/html/HTMLMediaElement.h b/Source/core/html/HTMLMediaElement.h
index 3561923f765376bdb21bb63c0be635c4f16354d4..3c331da4bfc147a9c39bf0596f635796007311bd 100644
--- a/Source/core/html/HTMLMediaElement.h
+++ b/Source/core/html/HTMLMediaElement.h
@@ -274,6 +274,10 @@ public:
     // and m_mediaController multipliers into account.
     double playerVolume() const;
 
+#if ENABLE(OILPAN)
+    bool isFinalizing() const { return m_isFinalizing; }
+#endif
+
 protected:
     HTMLMediaElement(const QualifiedName&, Document&);
     virtual ~HTMLMediaElement();
@@ -502,6 +506,9 @@ private:
     bool m_tracksAreReady : 1;
     bool m_haveVisibleTextTrack : 1;
     bool m_processingPreferenceChange : 1;
+#if ENABLE(OILPAN)
+    bool m_isFinalizing : 1;
+#endif
     double m_lastTextTrackUpdateTime;
 
     RefPtrWillBeMember<TextTrackList> m_textTracks;