Remove ENCRYPTED_MEDIA_V2 as it is always set.

Source/core/html/HTMLMediaElement.idl

 /*
  * Copyright (C) 2007, 2010, 2011, 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 82 matching lines @@
     // FIXME: add DeprecateAs=PrefixedMediaGenerateKeyRequest when MediaKeys is ready.
     [RuntimeEnabled=PrefixedEncryptedMedia, RaisesException] void webkitGenerateKeyRequest([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, optional Uint8Array initData);
     [RuntimeEnabled=PrefixedEncryptedMedia, RaisesException] void webkitAddKey([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, Uint8Array key, optional Uint8Array initData, [Default=NullString] optional DOMString sessionId);
     [RuntimeEnabled=PrefixedEncryptedMedia, RaisesException] void webkitCancelKeyRequest([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, [Default=NullString] optional DOMString sessionId);
 
     [RuntimeEnabled=PrefixedEncryptedMedia] attribute EventHandler onwebkitkeyadded;
     [RuntimeEnabled=PrefixedEncryptedMedia] attribute EventHandler onwebkitkeyerror;
     [RuntimeEnabled=PrefixedEncryptedMedia] attribute EventHandler onwebkitkeymessage;
     [RuntimeEnabled=PrefixedEncryptedMedia] attribute EventHandler onwebkitneedkey;
 
-    [RuntimeEnabled=EncryptedMedia, Conditional=ENCRYPTED_MEDIA_V2] attribute MediaKeys mediaKeys;
+    [RuntimeEnabled=EncryptedMedia] attribute MediaKeys mediaKeys;
 };