Use correct theme for the off icon of NightLight, fix tooltip and a11y

ash/BUILD.gn

 # 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 
 # Historical note: Ash shipped on Windows for a couple years to support
@@ skipping 403 matching lines @@
     "system/network/tray_vpn.cc",
     "system/network/tray_vpn.h",
     "system/network/vpn_list.cc",
     "system/network/vpn_list.h",
     "system/network/vpn_list_view.cc",
     "system/network/vpn_list_view.h",
     "system/networking_config_delegate.cc",
     "system/networking_config_delegate.h",
     "system/night_light/night_light_controller.cc",
     "system/night_light/night_light_controller.h",
+    "system/night_light/night_light_toggle_button.cc",
+    "system/night_light/night_light_toggle_button.h",
     "system/night_light/tray_night_light.cc",
     "system/night_light/tray_night_light.h",
     "system/overview/overview_button_tray.cc",
     "system/overview/overview_button_tray.h",
     "system/palette/common_palette_tool.cc",
     "system/palette/common_palette_tool.h",
     "system/palette/palette_ids.cc",
     "system/palette/palette_ids.h",
     "system/palette/palette_tool.cc",
     "system/palette/palette_tool.h",
@@ skipping 1080 matching lines @@
     "//content/public/app:both",
     "//device/bluetooth",
   ]
 
   data_deps = [
     "//ash/strings:ash_test_strings",
     "//ash/resources:ash_test_resources_with_content_100_percent",
     "//ash/resources:ash_test_resources_200_percent",
   ]
 }