feat(dark-mode): add force dark mode

src/dao/browser/dao_pref_names.cc

@@ -4,7 +4,17 @@
 
 #include "dao/browser/dao_pref_names.h"
 
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_window/public/browser_window_interface.h"
+#include "chrome/browser/ui/browser_window/public/browser_window_interface_iterator.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "components/pref_registry/pref_registry_syncable.h"
+#include "components/prefs/pref_service.h"
+#include "content/public/browser/web_contents.h"
+#include "third_party/blink/public/common/web_preferences/web_preferences.h"
+#include "third_party/blink/public/mojom/css/preferred_color_scheme.mojom.h"
+#include "ui/native_theme/native_theme.h"
 
 namespace dao::prefs {
 
@@ -15,6 +25,7 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(kDaoEnhancedPipEnabled, true);
   registry->RegisterBooleanPref(kDaoWelcomeShown, false);
   registry->RegisterBooleanPref(kDaoLittleDaoEnabled, true);
+  registry->RegisterBooleanPref(kDaoForceDarkModeEnabled, false);
   registry->RegisterBooleanPref(kDaoEnhancedCommandBarSuggestionsEnabled,
                                 false);
   registry->RegisterDictionaryPref(kDaoLittleDaoWindowSize);
@@ -24,3 +35,97 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
 }
 
 }  // namespace dao::prefs
+
+namespace dao {
+
+namespace {
+
+Profile* GetStorageProfile(Profile* profile) {
+  return profile ? profile->GetOriginalProfile() : nullptr;
+}
+
+bool UsesSameStorageProfile(Profile* lhs, Profile* rhs) {
+  return GetStorageProfile(lhs) == GetStorageProfile(rhs);
+}
+
+}  // namespace
+
+bool IsSystemDarkMode() {
+  ui::NativeTheme* theme = ui::NativeTheme::GetInstanceForNativeUi();
+  return theme && theme->preferred_color_scheme() ==
+                      ui::NativeTheme::PreferredColorScheme::kDark;
+}
+
+bool IsForceDarkModeUserEnabled(Profile* profile) {
+  Profile* storage_profile = GetStorageProfile(profile);
+  return storage_profile && storage_profile->GetPrefs()->GetBoolean(
+                                prefs::kDaoForceDarkModeEnabled);
+}
+
+bool IsForceDarkModeAvailable() {
+  return IsSystemDarkMode();
+}
+
+bool IsForceDarkModeEffective(Profile* profile) {
+  return IsForceDarkModeAvailable() && IsForceDarkModeUserEnabled(profile);
+}
+
+void SetForceDarkModeUserEnabled(Profile* profile, bool enabled) {
+  Profile* storage_profile = GetStorageProfile(profile);
+  if (!storage_profile) {
+    return;
+  }
+  storage_profile->GetPrefs()->SetBoolean(prefs::kDaoForceDarkModeEnabled,
+                                          enabled);
+  NotifyForceDarkModeChanged(storage_profile);
+}
+
+void ApplyForceDarkModePreferences(
+    Profile* profile,
+    blink::web_pref::WebPreferences* web_preferences) {
+  if (!web_preferences) {
+    return;
+  }
+
+  const bool force_dark_mode = IsForceDarkModeEffective(profile);
+  web_preferences->force_dark_mode_enabled = force_dark_mode;
+  if (!force_dark_mode) {
+    return;
+  }
+
+  web_preferences->preferred_color_scheme =
+      blink::mojom::PreferredColorScheme::kDark;
+  web_preferences->preferred_root_scrollbar_color_scheme =
+      blink::mojom::PreferredColorScheme::kDark;
+}
+
+void NotifyForceDarkModeChanged(Profile* profile) {
+  Profile* storage_profile = GetStorageProfile(profile);
+  if (!storage_profile) {
+    return;
+  }
+
+  for (BrowserWindowInterface* browser_window :
+       GetAllBrowserWindowInterfaces()) {
+    Browser* browser =
+        browser_window ? browser_window->GetBrowserForMigrationOnly() : nullptr;
+    if (!browser ||
+        !UsesSameStorageProfile(browser->profile(), storage_profile)) {
+      continue;
+    }
+
+    TabStripModel* tab_strip_model = browser->tab_strip_model();
+    if (!tab_strip_model) {
+      continue;
+    }
+
+    for (int i = 0; i < tab_strip_model->count(); ++i) {
+      content::WebContents* contents = tab_strip_model->GetWebContentsAt(i);
+      if (contents) {
+        contents->OnWebPreferencesChanged();
+      }
+    }
+  }
+}
+
+}  // namespace dao

src/dao/browser/dao_pref_names.h

@@ -5,6 +5,12 @@
 #ifndef DAO_BROWSER_DAO_PREF_NAMES_H_
 #define DAO_BROWSER_DAO_PREF_NAMES_H_
 
+class Profile;
+
+namespace blink::web_pref {
+struct WebPreferences;
+}
+
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
@@ -40,6 +46,12 @@ inline constexpr char kDaoWelcomeShown[] = "dao.welcome_shown";
 // When false, external links use the regular full browser window.
 inline constexpr char kDaoLittleDaoEnabled[] = "dao.little_dao_enabled";
 
+// Boolean pref that remembers whether Dao should use Chromium's Auto Dark Mode
+// pipeline for web contents. It only takes effect while the system appearance
+// is dark.
+inline constexpr char kDaoForceDarkModeEnabled[] =
+    "dao.force_dark_mode_enabled";
+
 // Boolean pref that enables the richer Arc-style command bar suggestion
 // pipeline. Kept off by default while the ranking model is still maturing.
 inline constexpr char kDaoEnhancedCommandBarSuggestionsEnabled[] =
@@ -68,4 +80,19 @@ inline constexpr char kDaoDreamExcludedDomains[] =
 
 }  // namespace dao::prefs
 
+namespace dao {
+
+bool IsSystemDarkMode();
+bool IsForceDarkModeUserEnabled(Profile* profile);
+bool IsForceDarkModeAvailable();
+bool IsForceDarkModeEffective(Profile* profile);
+
+void SetForceDarkModeUserEnabled(Profile* profile, bool enabled);
+void ApplyForceDarkModePreferences(
+    Profile* profile,
+    blink::web_pref::WebPreferences* web_preferences);
+void NotifyForceDarkModeChanged(Profile* profile);
+
+}  // namespace dao
+
 #endif  // DAO_BROWSER_DAO_PREF_NAMES_H_

src/dao/browser/strings/dao_strings.grd

@@ -336,6 +336,9 @@
       <message name="IDS_DAO_CONTROL_CENTER_BACK_BUTTON_ACCESSIBLE_NAME" desc="Accessible name for the back button in the Control Center 'More' submenu (no arrow, screen reader friendly).">
         Back
       </message>
+      <message name="IDS_DAO_CONTROL_CENTER_SHARE" desc="Label on the button in the Control Center 'More' submenu that opens the native share sheet for the current page.">
+        Share
+      </message>
       <message name="IDS_DAO_CONTROL_CENTER_CLEAR_CACHE" desc="Label on the button in the Control Center 'More' submenu that clears the browser cache. Idle state.">
         Clear Cache
       </message>
@@ -345,6 +348,18 @@
       <message name="IDS_DAO_CONTROL_CENTER_CLEARING" desc="Transient label shown on a Clear Cache or Clear Cookies button while the operation is in progress.">
         Clearing...
       </message>
+      <message name="IDS_DAO_FORCE_DARK_MODE_LABEL" desc="Accessible label for a toggle button that remembers whether Dao should force websites into dark mode while the system appearance is dark.">
+        Force dark mode
+      </message>
+      <message name="IDS_DAO_FORCE_DARK_MODE_SHORT_LABEL" desc="Short label shown under the Control Center utility button for the force dark mode toggle.">
+        Dark
+      </message>
+      <message name="IDS_DAO_FORCE_DARK_MODE_TOOLTIP" desc="Tooltip for the Force dark mode toggle when it can be changed because the system appearance is dark.">
+        Darken websites with Auto Dark Mode while the system is in dark mode.
+      </message>
+      <message name="IDS_DAO_FORCE_DARK_MODE_DISABLED_TOOLTIP" desc="Tooltip for the Force dark mode toggle when it is disabled because the system appearance is light.">
+        Available when the system is in dark mode.
+      </message>
 
       <!-- QR code dialog (after scanning a QR via right-click on an image) -->
       <message name="IDS_DAO_CONTEXT_MENU_DECODE_QR_CODE" desc="Image right-click context menu item that decodes any QR code embedded in the image and shows the result.">