[oilpan] Figure out lifetime of remaining Node raw pointers (Part 2)

Source/modules/encryptedmedia/MediaKeys.h

Index: Source/modules/encryptedmedia/MediaKeys.h
diff --git a/Source/modules/encryptedmedia/MediaKeys.h b/Source/modules/encryptedmedia/MediaKeys.h
index b724994cb6a5936c5229a1fb25af35880fc9f417..f48f165f43168eba9b36e604d032d01691a73875 100644
--- a/Source/modules/encryptedmedia/MediaKeys.h
+++ b/Source/modules/encryptedmedia/MediaKeys.h
@@ -53,8 +53,8 @@ public:
     const String& keySystem() const { return m_keySystem; }
     CDM* cdm() { return m_cdm.get(); }
 
-    HTMLMediaElement* mediaElement() const { return m_mediaElement; }
-    void setMediaElement(HTMLMediaElement*);
+    Result<HTMLMediaElement> mediaElement() const { return adoptRawResult(m_mediaElement); }
+    void setMediaElement(const Handle<HTMLMediaElement>&);
 
 protected:
     // CDMClient:
@@ -64,6 +64,8 @@ protected:
 
     Vector<RefPtr<MediaKeySession> > m_sessions;
 
+    // FIXME(oilpan): This is a strong pointer.
+    // MediaKeys and HTMLMediaElement should die together.
     HTMLMediaElement* m_mediaElement;
     String m_keySystem;
     OwnPtr<CDM> m_cdm;