Move kDarkLightMode feature from ash to chromeos.

It's needed in lacros-chrome. For the sake of reducing churn at ~50
callsites, ash::features::IsDarkLightModeEnabled() is left in place as
a thunk to chromeos::features::IsDarkLightModeEnabled().

This also brings the about:flags entry to Lacros.

Bug: 1278862
Change-Id: I8d8ee204888d5a9857dc7891c0092e8a99cffb51
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3339778
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Min Chen <minch@chromium.org>
Commit-Queue: Evan Stade <estade@chromium.org>
Cr-Commit-Position: refs/heads/main@{#952049}

diff --git a/ash/BUILD.gn b/ash/BUILD.gn
index 0812dd74..8b298f3 100644
--- a/ash/BUILD.gn
+++ b/ash/BUILD.gn

@@ -2748,6 +2748,7 @@
     "//chromeos/components/sensors:sensors",
     "//chromeos/components/sensors:test_support",
     "//chromeos/components/sensors/mojom",
+    "//chromeos/constants",
     "//chromeos/dbus:test_support",
     "//chromeos/dbus/audio",
     "//chromeos/dbus/hammerd",

diff --git a/ash/DEPS b/ash/DEPS
index 6e2b0963..f07d3bc 100644
--- a/ash/DEPS
+++ b/ash/DEPS

@@ -61,6 +61,7 @@
   "+chromeos/components/multidevice",
   "+chromeos/components/quick_answers",
   "+chromeos/components/sensors",
+  "+chromeos/constants",
   # crosapi is an API to support lacros.
   "+chromeos/crosapi",
   # //ash can access all D-Bus client libraries. The mustash project previously

diff --git a/ash/app_list/views/assistant/assistant_dialog_plate_unittest.cc b/ash/app_list/views/assistant/assistant_dialog_plate_unittest.cc
index 2f2cc15..12ced5ef 100644
--- a/ash/app_list/views/assistant/assistant_dialog_plate_unittest.cc
+++ b/ash/app_list/views/assistant/assistant_dialog_plate_unittest.cc

@@ -8,13 +8,13 @@
 #include "ash/assistant/test/assistant_ash_test_base.h"
 #include "ash/assistant/ui/assistant_ui_constants.h"
 #include "ash/assistant/ui/assistant_view_ids.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/style/color_provider.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shell.h"
 #include "ash/style/ash_color_provider.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/views/controls/textfield/textfield.h"
 
@@ -23,10 +23,11 @@
 using AssistantDialogPlateTest = AssistantAshTestBase;
 
 TEST_F(AssistantDialogPlateTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
   ASSERT_FALSE(ColorProvider::Get()->IsDarkModeEnabled());
 
   ShowAssistantUi();
@@ -50,7 +51,7 @@
 }
 
 TEST_F(AssistantDialogPlateTest, DarkAndLightModeFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   ShowAssistantUi();
 

diff --git a/ash/app_list/views/assistant/assistant_main_stage_unittest.cc b/ash/app_list/views/assistant/assistant_main_stage_unittest.cc
index b4b2baa..e02c537 100644
--- a/ash/app_list/views/assistant/assistant_main_stage_unittest.cc
+++ b/ash/app_list/views/assistant/assistant_main_stage_unittest.cc

@@ -13,6 +13,7 @@
 #include "ash/shell.h"
 #include "ash/style/ash_color_provider.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/color_palette.h"
@@ -44,7 +45,8 @@
 };
 
 TEST_F(AssistantMainStageTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
   ASSERT_TRUE(features::IsDarkLightModeEnabled());

diff --git a/ash/app_list/views/assistant/assistant_page_view_unittest.cc b/ash/app_list/views/assistant/assistant_page_view_unittest.cc
index 419e750..c410e9f 100644
--- a/ash/app_list/views/assistant/assistant_page_view_unittest.cc
+++ b/ash/app_list/views/assistant/assistant_page_view_unittest.cc

@@ -19,6 +19,7 @@
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkColor.h"
@@ -932,7 +933,7 @@
 
 TEST_F(AssistantPageNonBubbleTest, ThemeDarkLightMode) {
   base::test::ScopedFeatureList scoped_feature_list_enable_dark_light_mode(
-      features::kDarkLightMode);
+      chromeos::features::kDarkLightMode);
   base::test::ScopedFeatureList scoped_feature_list_disable_blur;
   scoped_feature_list_disable_blur.InitAndDisableFeature(
       features::kEnableBackgroundBlur);
@@ -974,7 +975,8 @@
 }
 
 TEST_F(AssistantPageNonBubbleTest, ThemeDarkLightModeWithBlur) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
   ASSERT_TRUE(features::IsBackgroundBlurEnabled());
@@ -1036,7 +1038,8 @@
 TEST_F(AssistantPageBubbleTest, BackgroundColorInDarkLightMode) {
   ASSERT_TRUE(features::IsProductivityLauncherEnabled());
 
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
   ASSERT_FALSE(ColorProvider::Get()->IsDarkModeEnabled());

diff --git a/ash/assistant/assistant_controller_impl_unittest.cc b/ash/assistant/assistant_controller_impl_unittest.cc
index 109bed5f..9fac96b 100644
--- a/ash/assistant/assistant_controller_impl_unittest.cc
+++ b/ash/assistant/assistant_controller_impl_unittest.cc

@@ -11,7 +11,6 @@
 #include "ash/assistant/test/assistant_ash_test_base.h"
 #include "ash/assistant/test/test_assistant_service.h"
 #include "ash/assistant/util/deep_link_util.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/assistant/controller/assistant_controller_observer.h"
 #include "ash/public/cpp/test/test_new_window_delegate.h"
@@ -20,6 +19,7 @@
 #include "ash/style/ash_color_provider.h"
 #include "base/scoped_observation.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
@@ -245,7 +245,7 @@
 // flag is off. SettingsController won't set options if dark mode bit is not
 // set.
 TEST_F(AssistantControllerImplTest, ColorModeIsSetWhenAssistantIsReadyFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   controller()->SetAssistant(test_assistant_service());
 
@@ -255,9 +255,9 @@
 
 TEST_F(AssistantControllerImplTest, ColorModeIsUpdated) {
   base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(features::kDarkLightMode);
+  feature_list.InitAndEnableFeature(chromeos::features::kDarkLightMode);
 
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
 
   // AshColorProvider::IsDarkModeEnabled reports it's in dark mode if active
   // pref service is not set.

diff --git a/ash/assistant/ui/DEPS b/ash/assistant/ui/DEPS
index 1bc71ee..17f1d5c 100644
--- a/ash/assistant/ui/DEPS
+++ b/ash/assistant/ui/DEPS

@@ -15,6 +15,7 @@
   "+cc/base",
   "+cc/paint",
   "+chromeos/assistant",
+  "+chromeos/constants",
   "+chromeos/services/assistant/public",
   "+chromeos/services/libassistant/public/cpp",
   "+mojo/public/cpp",

diff --git a/ash/assistant/ui/colors/assistant_colors_util_unittest.cc b/ash/assistant/ui/colors/assistant_colors_util_unittest.cc
index 7159e92..e7f4858 100644
--- a/ash/assistant/ui/colors/assistant_colors_util_unittest.cc
+++ b/ash/assistant/ui/colors/assistant_colors_util_unittest.cc

@@ -5,13 +5,13 @@
 #include "ash/assistant/ui/colors/assistant_colors_util.h"
 
 #include "ash/assistant/ui/colors/assistant_colors.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shell.h"
 #include "ash/style/ash_color_provider.h"
 #include "ash/test/ash_test_base.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkColor.h"
 
@@ -21,7 +21,8 @@
 using AssistantColorsUtilUnittest = AshTestBase;
 
 TEST_F(AssistantColorsUtilUnittest, AssistantColor) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
 
@@ -42,7 +43,7 @@
 }
 
 TEST_F(AssistantColorsUtilUnittest, AssistantColorFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   EXPECT_EQ(
       ResolveAssistantColor(assistant_colors::ColorName::kBgAssistantPlate),
@@ -55,7 +56,7 @@
 // ResolveAssistantColor falls back to assistant_colors::ResolveColor with dark
 // mode off if the color is not defined in the cc file map and the flag is off.
 TEST_F(AssistantColorsUtilUnittest, AssistantColorFlagOffFallback) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   EXPECT_EQ(ResolveAssistantColor(assistant_colors::ColorName::kGoogleBlue100),
             assistant_colors::ResolveColor(

diff --git a/ash/assistant/ui/main_stage/assistant_onboarding_suggestion_view_unittest.cc b/ash/assistant/ui/main_stage/assistant_onboarding_suggestion_view_unittest.cc
index 9d5fabc..a9b6579 100644
--- a/ash/assistant/ui/main_stage/assistant_onboarding_suggestion_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/assistant_onboarding_suggestion_view_unittest.cc

@@ -12,6 +12,7 @@
 #include "ash/style/ash_color_provider.h"
 #include "ash/test/ash_test_base.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/libassistant/public/cpp/assistant_suggestion.h"
 #include "components/prefs/pref_service.h"
 #include "ui/gfx/color_palette.h"
@@ -42,7 +43,8 @@
 using AssistantOnboardingSuggestionViewTest = AshTestBase;
 
 TEST_F(AssistantOnboardingSuggestionViewTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
   ASSERT_TRUE(features::IsDarkLightModeEnabled());

diff --git a/ash/assistant/ui/main_stage/assistant_onboarding_view_unittest.cc b/ash/assistant/ui/main_stage/assistant_onboarding_view_unittest.cc
index f92c721..e6eee08 100644
--- a/ash/assistant/ui/main_stage/assistant_onboarding_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/assistant_onboarding_view_unittest.cc

@@ -17,7 +17,6 @@
 #include "ash/assistant/ui/main_stage/assistant_onboarding_suggestion_view.h"
 #include "ash/assistant/ui/test_support/mock_assistant_view_delegate.h"
 #include "ash/assistant/util/test_support/macros.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/assistant/controller/assistant_suggestions_controller.h"
 #include "ash/public/cpp/assistant/controller/assistant_ui_controller.h"
@@ -31,6 +30,7 @@
 #include "base/test/icu_test_util.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/unguessable_token.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "chromeos/ui/vector_icons/vector_icons.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -468,10 +468,11 @@
 }
 
 TEST_F(AssistantOnboardingViewTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
   ASSERT_FALSE(ColorProvider::Get()->IsDarkModeEnabled());
 
   ShowAssistantUi();
@@ -496,7 +497,7 @@
 }
 
 TEST_F(AssistantOnboardingViewTest, DarkAndLightModeFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   ShowAssistantUi();
 

diff --git a/ash/assistant/ui/main_stage/assistant_query_view_unittest.cc b/ash/assistant/ui/main_stage/assistant_query_view_unittest.cc
index 58bb6dbf..446ba2ae 100644
--- a/ash/assistant/ui/main_stage/assistant_query_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/assistant_query_view_unittest.cc

@@ -15,6 +15,7 @@
 #include "ash/style/ash_color_provider.h"
 #include "base/feature_list.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/chromeos/styles/cros_styles.h"
 #include "ui/compositor/layer.h"
@@ -28,7 +29,8 @@
 using AssistantQueryViewUnittest = AssistantAshTestBase;
 
 TEST_F(AssistantQueryViewUnittest, ThemeDarkLightMode) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
 
@@ -69,7 +71,7 @@
 }
 
 TEST_F(AssistantQueryViewUnittest, Theme) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   ShowAssistantUi();
 

diff --git a/ash/assistant/ui/main_stage/assistant_text_element_view_unittest.cc b/ash/assistant/ui/main_stage/assistant_text_element_view_unittest.cc
index def24dab..5b9a61f 100644
--- a/ash/assistant/ui/main_stage/assistant_text_element_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/assistant_text_element_view_unittest.cc

@@ -5,7 +5,6 @@
 #include "ash/assistant/ui/main_stage/assistant_text_element_view.h"
 
 #include "ash/assistant/ui/assistant_ui_constants.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/style/color_provider.h"
 #include "ash/session/session_controller_impl.h"
@@ -13,6 +12,7 @@
 #include "ash/style/ash_color_provider.h"
 #include "ash/test/ash_test_base.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/widget/widget.h"
 
@@ -25,10 +25,11 @@
 using AssistantTextElementViewTest = AshTestBase;
 
 TEST_F(AssistantTextElementViewTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
   ASSERT_FALSE(ColorProvider::Get()->IsDarkModeEnabled());
 
   std::unique_ptr<views::Widget> widget = CreateFramelessTestWidget();
@@ -52,7 +53,7 @@
 }
 
 TEST_F(AssistantTextElementViewTest, DarkAndLightModeFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   std::unique_ptr<views::Widget> widget = CreateFramelessTestWidget();
   AssistantTextElementView* text_element_view = widget->SetContentsView(

diff --git a/ash/assistant/ui/main_stage/assistant_zero_state_view_unittest.cc b/ash/assistant/ui/main_stage/assistant_zero_state_view_unittest.cc
index 24a7c31..077167d2 100644
--- a/ash/assistant/ui/main_stage/assistant_zero_state_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/assistant_zero_state_view_unittest.cc

@@ -8,12 +8,12 @@
 #include "ash/assistant/ui/assistant_ui_constants.h"
 #include "ash/assistant/ui/assistant_view_ids.h"
 #include "ash/assistant/ui/colors/assistant_colors.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shell.h"
 #include "ash/style/ash_color_provider.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/chromeos/styles/cros_styles.h"
 #include "ui/views/controls/label.h"
@@ -24,7 +24,7 @@
 using AssistantZeroStateViewUnittest = AssistantAshTestBase;
 
 TEST_F(AssistantZeroStateViewUnittest, Theme) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   ShowAssistantUi();
 
@@ -36,7 +36,8 @@
 }
 
 TEST_F(AssistantZeroStateViewUnittest, ThemeDarkLightMode) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
 

diff --git a/ash/assistant/ui/main_stage/suggestion_chip_view_unittest.cc b/ash/assistant/ui/main_stage/suggestion_chip_view_unittest.cc
index a9b5480..6b6ce70f 100644
--- a/ash/assistant/ui/main_stage/suggestion_chip_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/suggestion_chip_view_unittest.cc

@@ -8,7 +8,6 @@
 #include "ash/assistant/ui/assistant_view_ids.h"
 #include "ash/assistant/ui/test_support/mock_assistant_view_delegate.h"
 #include "ash/assistant/util/test_support/macros.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/style/color_provider.h"
 #include "ash/session/session_controller_impl.h"
@@ -18,6 +17,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "cc/paint/paint_flags.h"
 #include "cc/test/pixel_comparator.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/assistant/public/cpp/assistant_service.h"
 #include "chromeos/ui/vector_icons/vector_icons.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -124,10 +124,11 @@
 }
 
 TEST_F(SuggestionChipViewTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
   ASSERT_FALSE(ColorProvider::Get()->IsDarkModeEnabled());
 
   auto widget = CreateFramelessTestWidget();
@@ -199,7 +200,7 @@
 }
 
 TEST_F(SuggestionChipViewTest, DarkAndLightModeFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   auto widget = CreateFramelessTestWidget();
   auto* suggestion_chip_view =

diff --git a/ash/assistant/ui/main_stage/ui_element_container_view_unittest.cc b/ash/assistant/ui/main_stage/ui_element_container_view_unittest.cc
index 55d7c4ab..ceb589b5 100644
--- a/ash/assistant/ui/main_stage/ui_element_container_view_unittest.cc
+++ b/ash/assistant/ui/main_stage/ui_element_container_view_unittest.cc

@@ -7,7 +7,6 @@
 #include "ash/assistant/assistant_interaction_controller_impl.h"
 #include "ash/assistant/test/assistant_ash_test_base.h"
 #include "ash/assistant/ui/assistant_view_ids.h"
-#include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
 #include "ash/public/cpp/assistant/controller/assistant_interaction_controller.h"
 #include "ash/session/session_controller_impl.h"
@@ -15,6 +14,7 @@
 #include "ash/style/ash_color_provider.h"
 #include "base/test/scoped_feature_list.h"
 #include "cc/base/math_util.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "chromeos/services/libassistant/public/cpp/assistant_interaction_metadata.h"
 #include "ui/compositor/layer.h"
 #include "ui/gfx/color_palette.h"
@@ -32,10 +32,11 @@
 using UiElementContainerViewTest = AssistantAshTestBase;
 
 TEST_F(UiElementContainerViewTest, DarkAndLightTheme) {
-  base::test::ScopedFeatureList scoped_feature_list(features::kDarkLightMode);
+  base::test::ScopedFeatureList scoped_feature_list(
+      chromeos::features::kDarkLightMode);
   AshColorProvider::Get()->OnActiveUserPrefServiceChanged(
       Shell::Get()->session_controller()->GetActivePrefService());
-  ASSERT_TRUE(features::IsDarkLightModeEnabled());
+  ASSERT_TRUE(chromeos::features::IsDarkLightModeEnabled());
   ASSERT_FALSE(AshColorProvider::Get()->IsDarkModeEnabled());
 
   ShowAssistantUi();
@@ -58,7 +59,7 @@
 }
 
 TEST_F(UiElementContainerViewTest, DarkAndLightModeFlagOff) {
-  ASSERT_FALSE(features::IsDarkLightModeEnabled());
+  ASSERT_FALSE(chromeos::features::IsDarkLightModeEnabled());
 
   ShowAssistantUi();
 

diff --git a/ash/constants/BUILD.gn b/ash/constants/BUILD.gn
index ebcd13a..bbf5dab 100644
--- a/ash/constants/BUILD.gn
+++ b/ash/constants/BUILD.gn

@@ -26,6 +26,7 @@
   ]
   public_deps = [
     "//base",
+    "//chromeos/constants",
     "//skia",
     "//third_party/abseil-cpp:absl",
   ]

diff --git a/ash/constants/DEPS b/ash/constants/DEPS
index 0eda6c8..6a39252 100644
--- a/ash/constants/DEPS
+++ b/ash/constants/DEPS

@@ -5,6 +5,7 @@
   "+ash/constants",
   "+base",
   "+build",
+  "+chromeos/constants",
   "+third_party/abseil-cpp/absl/types/optional.h",
 ]
 

diff --git a/ash/constants/ash_features.cc b/ash/constants/ash_features.cc
index 2cf5855..acf18902d 100644
--- a/ash/constants/ash_features.cc
+++ b/ash/constants/ash_features.cc

@@ -10,6 +10,7 @@
 #include "base/metrics/field_trial_params.h"
 #include "base/system/sys_info.h"
 #include "build/build_config.h"
+#include "chromeos/constants/chromeos_features.h"
 
 namespace ash {
 namespace features {
@@ -369,10 +370,6 @@
 const base::Feature kCryptohomeRecoveryFlow{"CryptohomeRecoveryFlow",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Enables dark/light mode feature.
-const base::Feature kDarkLightMode{"DarkLightMode",
-                                   base::FEATURE_DISABLED_BY_DEFAULT};
-
 const base::Feature kDemoModeSWA{"DemoModeSWA",
                                  base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -1446,7 +1443,7 @@
 }
 
 bool IsDarkLightModeEnabled() {
-  return base::FeatureList::IsEnabled(kDarkLightMode);
+  return chromeos::features::IsDarkLightModeEnabled();
 }
 
 bool IsDemoModeSWAEnabled() {

diff --git a/ash/constants/ash_features.h b/ash/constants/ash_features.h
index b34e082..56d9c8b6 100644
--- a/ash/constants/ash_features.h
+++ b/ash/constants/ash_features.h

@@ -152,7 +152,6 @@
 extern const base::Feature kCryptAuthV2Enrollment;
 COMPONENT_EXPORT(ASH_CONSTANTS)
 extern const base::Feature kCryptohomeRecoveryFlow;
-COMPONENT_EXPORT(ASH_CONSTANTS) extern const base::Feature kDarkLightMode;
 COMPONENT_EXPORT(ASH_CONSTANTS) extern const base::Feature kDemoModeSWA;
 COMPONENT_EXPORT(ASH_CONSTANTS) extern const base::Feature kDeskTemplateSync;
 COMPONENT_EXPORT(ASH_CONSTANTS) extern const base::Feature kDeviceActiveClient;

diff --git a/ash/style/ash_color_provider_unittests.cc b/ash/style/ash_color_provider_unittests.cc
index df6e6d7..dd85bf3 100644
--- a/ash/style/ash_color_provider_unittests.cc
+++ b/ash/style/ash_color_provider_unittests.cc

@@ -4,10 +4,10 @@
 
 #include "ash/style/ash_color_provider.h"
 
-#include "ash/constants/ash_features.h"
 #include "ash/session/test_session_controller_client.h"
 #include "ash/test/ash_test_base.h"
 #include "base/test/scoped_feature_list.h"
+#include "chromeos/constants/chromeos_features.h"
 
 namespace ash {
 
@@ -21,7 +21,7 @@
   // When dark/light mode is enabled. Color mode in non-active user sessions
   // (e.g, login page) should be DARK, but LIGHT while in OOBE.
   base::test::ScopedFeatureList enable_dark_light;
-  enable_dark_light.InitAndEnableFeature(features::kDarkLightMode);
+  enable_dark_light.InitAndEnableFeature(chromeos::features::kDarkLightMode);
   client->SetSessionState(session_manager::SessionState::UNKNOWN);
   EXPECT_TRUE(color_provider->IsDarkModeEnabled());
   client->SetSessionState(session_manager::SessionState::OOBE);
@@ -30,7 +30,7 @@
   // When dark/light mode is disabled. Color mode in non-active user sessions
   // (e.g, login page) should still be DARK.
   base::test::ScopedFeatureList disable_dark_light;
-  disable_dark_light.InitAndDisableFeature(features::kDarkLightMode);
+  disable_dark_light.InitAndDisableFeature(chromeos::features::kDarkLightMode);
   client->SetSessionState(session_manager::SessionState::UNKNOWN);
   EXPECT_TRUE(color_provider->IsDarkModeEnabled());
   client->SetSessionState(session_manager::SessionState::OOBE);

diff --git a/ash/wallpaper/wallpaper_controller_unittest.cc b/ash/wallpaper/wallpaper_controller_unittest.cc
index e8b6c17..5529a97 100644
--- a/ash/wallpaper/wallpaper_controller_unittest.cc
+++ b/ash/wallpaper/wallpaper_controller_unittest.cc

@@ -48,6 +48,7 @@
 #include "base/test/scoped_feature_list.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time_override.h"
+#include "chromeos/constants/chromeos_features.h"
 #include "components/prefs/scoped_user_pref_update.h"
 #include "components/user_manager/fake_user_manager.h"
 #include "components/user_manager/scoped_user_manager.h"
@@ -3250,7 +3251,7 @@
   void SetUp() override {
     scoped_feature_list_.InitWithFeatures(
         {features::kWallpaperWebUI, features::kWallpaperFullScreenPreview,
-         features::kDarkLightMode},
+         chromeos::features::kDarkLightMode},
         {});
     WallpaperControllerTestBase::SetUp();
   }

diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 4109bff..e2b5687 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc

@@ -3005,9 +3005,6 @@
      flag_descriptions::kUseHDRTransferFunctionName,
      flag_descriptions::kUseHDRTransferFunctionDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(display::features::kUseHDRTransferFunction)},
-    {"dark-light-mode", flag_descriptions::kDarkLightTestName,
-     flag_descriptions::kDarkLightTestDescription, kOsCrOS,
-     FEATURE_VALUE_TYPE(ash::features::kDarkLightMode)},
     {"vertical-snap", flag_descriptions::kVerticalSnapName,
      flag_descriptions::kVerticalSnapDescription, kOsCrOS,
      FEATURE_VALUE_TYPE(chromeos::wm::features::kVerticalSnap)},
@@ -3229,6 +3226,9 @@
 #endif  // BUILDFLAG(IS_CHROMEOS_ASH)
 
 #if defined(OS_CHROMEOS)
+    {"dark-light-mode", flag_descriptions::kDarkLightTestName,
+     flag_descriptions::kDarkLightTestDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(chromeos::features::kDarkLightMode)},
     // TODO(b/180051795): remove kOsLinux when lacros-chrome switches to
     // kOsCrOS.
     {"deprecate-low-usage-codecs",

diff --git a/chromeos/constants/chromeos_features.cc b/chromeos/constants/chromeos_features.cc
index f9ff708..8a9cc785f 100644
--- a/chromeos/constants/chromeos_features.cc
+++ b/chromeos/constants/chromeos_features.cc

@@ -23,6 +23,10 @@
 const base::Feature kBluetoothPhoneFilter{"BluetoothPhoneFilter",
                                           base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables dark/light mode feature.
+const base::Feature kDarkLightMode{"DarkLightMode",
+                                   base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Disables translation services of the Quick Answers V2.
 const base::Feature kDisableQuickAnswersV2Translation{
     "DisableQuickAnswersV2Translation", base::FEATURE_DISABLED_BY_DEFAULT};
@@ -35,6 +39,10 @@
   return base::FeatureList::IsEnabled(kBluetoothAdvertisementMonitoring);
 }
 
+bool IsDarkLightModeEnabled() {
+  return base::FeatureList::IsEnabled(kDarkLightMode);
+}
+
 bool IsQuickAnswersV2TranslationDisabled() {
   return base::FeatureList::IsEnabled(kDisableQuickAnswersV2Translation);
 }

diff --git a/chromeos/constants/chromeos_features.h b/chromeos/constants/chromeos_features.h
index 6bd8e89..9c939cd 100644
--- a/chromeos/constants/chromeos_features.h
+++ b/chromeos/constants/chromeos_features.h

@@ -26,6 +26,7 @@
 extern const base::Feature kBluetoothAdvertisementMonitoring;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kBluetoothPhoneFilter;
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS) extern const base::Feature kDarkLightMode;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 extern const base::Feature kDisableQuickAnswersV2Translation;
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
@@ -35,6 +36,7 @@
 
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 bool IsBluetoothAdvertisementMonitoringEnabled();
+COMPONENT_EXPORT(CHROMEOS_CONSTANTS) bool IsDarkLightModeEnabled();
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS) bool IsQuickAnswersV2TranslationDisabled();
 COMPONENT_EXPORT(CHROMEOS_CONSTANTS)
 bool IsQuickAnswersV2SettingsSubToggleEnabled();