Add window overview mode behind --ash-enable-overview-mode flag to F5 key.

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 "base/command_line.h"
 
 namespace ash {
 namespace switches {
@@ skipping 96 matching lines @@
 const char kAshEnableImmersiveFullscreen[] = "ash-enable-immersive-fullscreen";
 
 #if defined(OS_LINUX)
 // Enable memory monitoring.
 const char kAshEnableMemoryMonitor[] = "ash-enable-memory-monitor";
 #endif
 
 // Enables the Oak tree viewer.
 const char kAshEnableOak[] = "ash-enable-oak";
 
+// Enables overview mode for window switching.
+const char kAshEnableOverviewMode[] = "ash-enable-overview-mode";
+
 // Enables "sticky" edges instead of "snap-to-edge"
 const char kAshEnableStickyEdges[] = "ash-enable-sticky-edges";
 
 // Enables showing the tray bubble by dragging on the shelf.
 const char kAshEnableTrayDragging[] = "ash-enable-tray-dragging";
 
 // Enable workspace switching via a three finger vertical scroll.
 const char kAshEnableWorkspaceScrubbing[] = "ash-enable-workspace-scrubbing";
 
 // Forces chrome to use mirror mode when an external display is connected.
@@ skipping 76 matching lines @@
 }
 
 bool UseUsbChargerNotification() {
   return !CommandLine::ForCurrentProcess()->
         HasSwitch(ash::switches::kAshDisableUsbChargerNotification);
 }
 #endif
 
 }  // namespace switches
 }  // namespace ash