Remove the (already disabled) OverflowChangedEvent runtime flag

Source/core/events/OverflowEvent.idl

Index: Source/core/events/OverflowEvent.idl
diff --git a/Source/core/events/OverflowEvent.idl b/Source/core/events/OverflowEvent.idl
deleted file mode 100644
index ea30d9f8e3a9607e8ca80adff24ccd540100c83b..0000000000000000000000000000000000000000
--- a/Source/core/events/OverflowEvent.idl
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * Copyright (C) 2006, 2007 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
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. 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.
- */
-
-// TODO(philipj): Remove the overflowchanged event. crbug.com/460822
-[
-    Constructor(DOMString type, optional OverflowEventInit eventInitDict),
-    RuntimeEnabled=OverflowChangedEvent,
-] interface OverflowEvent : Event {
-    const unsigned short HORIZONTAL = 0;
-    const unsigned short VERTICAL   = 1;
-    const unsigned short BOTH       = 2;
-
-    readonly attribute unsigned short orient;
-    readonly attribute boolean horizontalOverflow;
-    readonly attribute boolean verticalOverflow;
-};