Add mirrored screen option

ash/ash_switches.cc

Index: ash/ash_switches.cc
diff --git a/ash/ash_switches.cc b/ash/ash_switches.cc
index 1240839ba855551c80f697eec7b543627ed40928..61347e1fa382c54a732f8e7d9460b663ca05609e 100644
--- a/ash/ash_switches.cc
+++ b/ash/ash_switches.cc
@@ -48,15 +48,18 @@ const char kAshDisableLockLayoutManager[] = "ash-disable-lock-layout-manager";
 const char kAshDisableTouchExplorationMode[] =
     "ash-disable-touch-exploration-mode";
 
+// Enables text filtering with the keyboard in Overview Mode.
+const char kAshDisableTextFilteringInOverviewMode[] =
+    "ash-disable-text-filtering-in-overview-mode";
+
 #if defined(OS_CHROMEOS)
 // Enables key bindings to scroll magnified screen.
 const char kAshEnableMagnifierKeyScroller[] =
     "ash-enable-magnifier-key-scroller";
 #endif
 
-// Enables text filtering with the keyboard in Overview Mode.
-const char kAshDisableTextFilteringInOverviewMode[] =
-    "ash-disable-text-filtering-in-overview-mode";
+// Enables mirrored screen.
+const char kAshEnableMirroredScreen[] = "ash-enable-mirrored-screen";
 
 // Enables quick, non-cancellable locking of the screen when in maximize mode.
 const char kAshEnablePowerButtonQuickLock[] =