Show overview mode button in TouchView with open modal window

ash/system/overview/overview_button_tray.cc

Index: ash/system/overview/overview_button_tray.cc
diff --git a/ash/system/overview/overview_button_tray.cc b/ash/system/overview/overview_button_tray.cc
index edd5d67dd0697dd2598133cc5289d83e7511831f..e73e40135b071938e31f9fb45c2ea43320dbc972 100644
--- a/ash/system/overview/overview_button_tray.cc
+++ b/ash/system/overview/overview_button_tray.cc
@@ -115,9 +115,12 @@ void OverviewButtonTray::SetIconBorderForShelfAlignment() {
 }
 
 void OverviewButtonTray::UpdateIconVisibility() {
-  SetVisible(Shell::GetInstance()->maximize_mode_controller()->
-                 IsMaximizeModeWindowManagerEnabled() &&
-             Shell::GetInstance()->window_selector_controller()->CanSelect());
+  SetVisible(Shell::GetInstance()
+                 ->maximize_mode_controller()
+                 ->IsMaximizeModeWindowManagerEnabled() &&
+             Shell::GetInstance()
+                 ->window_selector_controller()
+                 ->IsUserInActiveDesktopEnvironment());
 }
 
 }  // namespace ash