dark_mode: Add feature flag kDarkLightMode.

Bug: 1106012
Change-Id: Ia7333c45367508ff4bc6f970ae67950ab494311f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2373948Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801866}

ash/public/cpp/ash_features.cc

@@ -44,6 +44,9 @@ const base::Feature kCaptureMode{"CaptureMode",
 const base::Feature kContextualNudges{"ContextualNudges",
                                       base::FEATURE_ENABLED_BY_DEFAULT};
 
+const base::Feature kDarkLightMode{"DarkLightMode",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
 const base::Feature kDisplayAlignAssist{"DisplayAlignAssist",
                                         base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -174,6 +177,10 @@ bool IsCaptureModeEnabled() {
   return base::FeatureList::IsEnabled(kCaptureMode);
 }
 
+bool IsDarkLightModeEnabled() {
+  return base::FeatureList::IsEnabled(kDarkLightMode);
+}
+
 bool IsHideArcMediaNotificationsEnabled() {
   return base::FeatureList::IsEnabled(kMediaSessionNotification) &&
          base::FeatureList::IsEnabled(kHideArcMediaNotifications);

ash/public/cpp/ash_features.h

@@ -28,6 +28,9 @@ ASH_PUBLIC_EXPORT extern const base::Feature kCaptureMode;
 // Enables contextual nudges for gesture education.
 ASH_PUBLIC_EXPORT extern const base::Feature kContextualNudges;
 
+// Enables dark/light mode feature.
+ASH_PUBLIC_EXPORT extern const base::Feature kDarkLightMode;
+
 // Enables indicators to hint where displays are connected.
 ASH_PUBLIC_EXPORT extern const base::Feature kDisplayAlignAssist;
 
@@ -181,6 +184,8 @@ ASH_PUBLIC_EXPORT bool IsAutoNightLightEnabled();
 
 ASH_PUBLIC_EXPORT bool IsCaptureModeEnabled();
 
+ASH_PUBLIC_EXPORT bool IsDarkLightModeEnabled();
+
 ASH_PUBLIC_EXPORT bool IsHideArcMediaNotificationsEnabled();
 
 ASH_PUBLIC_EXPORT bool IsKeyboardShortcutViewerAppEnabled();

ash/system/unified/unified_system_tray_controller.cc

@@ -22,6 +22,7 @@
 #include "ash/system/cast/cast_feature_pod_controller.h"
 #include "ash/system/cast/unified_cast_detailed_view_controller.h"
 #include "ash/system/dark_mode/dark_mode_detailed_view_controller.h"
+#include "ash/system/dark_mode/dark_mode_feature_pod_controller.h"
 #include "ash/system/ime/ime_feature_pod_controller.h"
 #include "ash/system/ime/unified_ime_detailed_view_controller.h"
 #include "ash/system/locale/locale_feature_pod_controller.h"
@@ -420,6 +421,8 @@ void UnifiedSystemTrayController::InitFeaturePods() {
   AddFeaturePodItem(std::make_unique<LocaleFeaturePodController>(this));
   if (features::IsCaptureModeEnabled())
     AddFeaturePodItem(std::make_unique<CaptureModeFeaturePodController>());
+  if (features::IsDarkLightModeEnabled())
+    AddFeaturePodItem(std::make_unique<DarkModeFeaturePodController>(this));
 
   // If you want to add a new feature pod item, add here.