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

Source/bindings/tests/idls/TestInterfacePython3.idl

Index: Source/bindings/tests/idls/TestInterfacePython3.idl
diff --git a/Source/modules/mediasource/SourceBufferList.idl b/Source/bindings/tests/idls/TestInterfacePython3.idl
similarity index 82%
copy from Source/modules/mediasource/SourceBufferList.idl
copy to Source/bindings/tests/idls/TestInterfacePython3.idl
index bbac1f0402d4e488756ab89239ab1ff48ef5cc55..c081d2c90d4513fa07a95aa35243511db61ff082 100644
--- a/Source/modules/mediasource/SourceBufferList.idl
+++ b/Source/bindings/tests/idls/TestInterfacePython3.idl
@@ -28,12 +28,11 @@
  * 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 {
 };
-