Revert of Make DOMWrapperWorld::current() return a reference instead of a pointer

Source/bindings/tests/idls/TestInterfacePython3.idl

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+// This is for interface extended attributes that interact with another extended
+// attribute, and thus both cannot be tested at once.
+// The more *minor* extended attribute should be put in this file.
+
 [
-    WillBeGarbageCollected,
-    NoInterfaceObject,
-    RuntimeEnabled=MediaSource,
-] interface SourceBufferList : EventTarget {
-    readonly attribute unsigned long length;
-    getter SourceBuffer item(unsigned long index);
+    Custom=VisitDOMWrapper,  // Conflict with [SetWrapperReferenceTo] and [SetWrapperReferenceFrom]
+] interface TestInterfacePython3 {
 };
-