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

Source/modules/encryptedmedia/MediaKeys.cpp

Index: Source/modules/encryptedmedia/MediaKeys.cpp
diff --git a/Source/modules/encryptedmedia/MediaKeys.cpp b/Source/modules/encryptedmedia/MediaKeys.cpp
index d5f76a1d2b4d95fb9eeadf53acd551177a959a8a..cfe9f0aac0ce030e13d4a0417964b10f1848fb9e 100644
--- a/Source/modules/encryptedmedia/MediaKeys.cpp
+++ b/Source/modules/encryptedmedia/MediaKeys.cpp
@@ -118,9 +118,9 @@ PassRefPtr<MediaKeySession> MediaKeys::createSession(ScriptExecutionContext* con
     return session;
 }
 
-void MediaKeys::setMediaElement(HTMLMediaElement* element)
+void MediaKeys::setMediaElement(const Handle<HTMLMediaElement>& element)
 {
-    m_mediaElement = element;
+    m_mediaElement = element.raw();
 }
 
 MediaPlayer* MediaKeys::cdmMediaPlayer(const CDM*) const