Show overview mode button in TouchView with open modal window

ash/system/overview/overview_button_tray.cc

 // Copyright 2014 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/system/overview/overview_button_tray.h"
 
 #include "ash/shelf/shelf_types.h"
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/tray_utils.h"
@@ skipping 97 matching lines @@
   } else {
     icon_->SetBorder(views::Border::CreateEmptyBorder(
         kVerticalShelfVerticalPadding,
         kVerticalShelfHorizontalPadding,
         kVerticalShelfVerticalPadding,
         kVerticalShelfHorizontalPadding));
   }
 }
 
 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