dark_mode: AUTO status string in system tray

Bug: 1307977
Test: Manual
Change-Id: Iac389fdf3379b9c03f0409c639da60336cfcd134
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3542433
Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Commit-Queue: Cattalyya Nuengsigkapian <cattalyya@chromium.org>
Cr-Commit-Position: refs/heads/main@{#987184}

ash/ash_strings.grd

@@ -453,6 +453,12 @@ This file contains the strings for ash.
       <message name="IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE" desc="Button label for the Dark theme feature." meaning="Dark theme feature is on. [CHAR_LIMIT=14]">
         On
       </message>
+      <message name="IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE_AUTO_SCHEDULED" desc="Button label for the Dark theme feature when auto scheduling is enabled." meaning="Dark mode is automatically scheduled to be on until sunrise. [CHAR_LIMIT=16]">
+        On until sunrise
+      </message>
+      <message name="IDS_ASH_STATUS_TRAY_DARK_THEME_OFF_STATE_AUTO_SCHEDULED" desc="Button label for the Dark theme feature when auto scheduling is enabled." meaning="Dark mode is automatically scheduled to be off until sunset. [CHAR_LIMIT=16]">
+        Off until sunset
+      </message>
       <message name="IDS_ASH_STATUS_TRAY_CAST_CAST_DESKTOP_ACCESSIBILITY_STOP" desc="Stop button accessibility label used in the tray popup to tell the user to stop a cast to the desktop.">
         Stop casting screen to <ph name="RECEIVER_NAME">$1<ex>Living Room</ex></ph>
       </message>

ash/ash_strings_grd/IDS_ASH_STATUS_TRAY_DARK_THEME_OFF_STATE_AUTO_SCHEDULED.png.sha1

@@ -0,0 +1 @@
+bdf636dc9512d2d9873945b213c03bebabf5a41c

ash/ash_strings_grd/IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE_AUTO_SCHEDULED.png.sha1

@@ -0,0 +1 @@
+0c768a66fe0ee51cd9c80abcb8fbed79f03b4bd6

ash/system/dark_mode/dark_mode_feature_pod_controller.cc

@@ -10,6 +10,7 @@
 #include "ash/shell.h"
 #include "ash/strings/grit/ash_strings.h"
 #include "ash/style/ash_color_provider.h"
+#include "ash/style/dark_mode_controller.h"
 #include "ash/system/model/system_tray_model.h"
 #include "ash/system/tray/tray_popup_utils.h"
 #include "ash/system/unified/feature_pod_button.h"
@@ -68,9 +69,16 @@ void DarkModeFeaturePodController::OnColorModeChanged(bool dark_mode_enabled) {
 
 void DarkModeFeaturePodController::UpdateButton(bool dark_mode_enabled) {
   button_->SetToggled(dark_mode_enabled);
-  button_->SetSubLabel(l10n_util::GetStringUTF16(
+  if (ash::Shell::Get()->dark_mode_controller()->GetAutoScheduleEnabled()) {
-      dark_mode_enabled ? IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE
+    button_->SetSubLabel(l10n_util::GetStringUTF16(
-                        : IDS_ASH_STATUS_TRAY_DARK_THEME_OFF_STATE));
+        dark_mode_enabled
+            ? IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE_AUTO_SCHEDULED
+            : IDS_ASH_STATUS_TRAY_DARK_THEME_OFF_STATE_AUTO_SCHEDULED));
+  } else {
+    button_->SetSubLabel(l10n_util::GetStringUTF16(
+        dark_mode_enabled ? IDS_ASH_STATUS_TRAY_DARK_THEME_ON_STATE
+                          : IDS_ASH_STATUS_TRAY_DARK_THEME_OFF_STATE));
+  }
 
   std::u16string tooltip_state = l10n_util::GetStringUTF16(
       dark_mode_enabled