Remove --ash-disable-overview-mode

ash/ash_switches.cc

Index: ash/ash_switches.cc
diff --git a/ash/ash_switches.cc b/ash/ash_switches.cc
index cd057dc23b097e122c85c6df2f888c6406880cf6..782dae7d6a2bd467a3c089e287b9ee825150f2e9 100644
--- a/ash/ash_switches.cc
+++ b/ash/ash_switches.cc
@@ -50,9 +50,6 @@ const char kAshDisableAlternateShelfLayout[] =
 // Disable ability to dock windows at the desktop edge.
 const char kAshDisableDockedWindows[] = "ash-disable-docked-windows";
 
-// Disables overview mode for window switching.
-const char kAshDisableOverviewMode[] = "ash-disable-overview-mode";
-
 // Enable advanced gestures (e.g. for window management).
 const char kAshEnableAdvancedGestures[] = "ash-enable-advanced-gestures";
 
@@ -161,10 +158,6 @@ bool UseImmersiveFullscreenForAllWindows() {
       kAshEnableImmersiveFullscreenForBrowserOnly);
 }
 
-bool UseOverviewMode() {
-  return !CommandLine::ForCurrentProcess()->HasSwitch(kAshDisableOverviewMode);
-}
-
 bool UseDockedWindows() {
   return !CommandLine::ForCurrentProcess()->HasSwitch(kAshDisableDockedWindows);
 }