Dismiss cros alt+tab UI on escape.

ash/wm/window_cycle_event_filter_aura.cc

Index: ash/wm/window_cycle_event_filter_aura.cc
diff --git a/ash/wm/window_cycle_event_filter_aura.cc b/ash/wm/window_cycle_event_filter_aura.cc
index 4dea0ade0d44d13a15d8f69a8abf4bd2f643f6a9..fbafa859b4bd3062689cf05afdcf48e6e7a6edd1 100644
--- a/ash/wm/window_cycle_event_filter_aura.cc
+++ b/ash/wm/window_cycle_event_filter_aura.cc
@@ -45,6 +45,8 @@ void WindowCycleEventFilterAura::OnKeyEvent(ui::KeyEvent* event) {
               event->IsShiftDown() ? WindowCycleController::BACKWARD
                                    : WindowCycleController::FORWARD));
     }
+  } else if (event->key_code() == ui::VKEY_ESCAPE) {
+    WmShell::Get()->window_cycle_controller()->StopCycling();
   }
 }