Aura: Remove overlapping window mode

ash/ash_switches.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/ash_switches.h"
 
 #include <string>
 
 #include "base/command_line.h"
 
@@ skipping 31 matching lines @@
 const char kAuraWindowMode[] = "aura-window-mode";
 
 // Show only a single maximized window, like traditional non-Aura builds.
 // Useful for low-resolution screens, such as on laptops.
 const char kAuraWindowModeCompact[] = "compact";
 
 // Smart window management with workspace manager that automatically lays out
 // windows.
 const char kAuraWindowModeManaged[] = "managed";
 
-// Traditional window management with multiple draggable windows.
-const char kAuraWindowModeOverlapping[] = "overlapping";
-
 // Use Aura to manage windows of type WINDOW_TYPE_PANEL.
 const char kAuraPanelManager[] = "aura-panels";
 
 }  // namespace switches
 }  // namespace ash