[CrossDevice] Disable Cross-device features on Flex with switch.

This updates the logic for disabling the Cross-device feature suite on
Flex. The build flag we previously used is not fully wired up, so we use
the "reven branding" switch instead per the Flex team's recommendation.

Test: Manually tested with "--reven-branding" switch to simulate Flex.
Also regression tested all features with the suite allowed.

Fixed: b:343212627
Change-Id: I51b843c52bc7a845fb73ea08b1966305df7ee5a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5593653
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Michael Hansen <hansenmichael@google.com>
Reviewed-by: Jon Mann <jonmann@chromium.org>
Reviewed-by: Jack Shira <jackshira@google.com>
Cr-Commit-Position: refs/heads/main@{#1311618}

ash/constants/ash_features.cc

@@ -66,15 +66,10 @@ BASE_FEATURE(kAllowAmbientEQ,
 // Enables Cross-Device features, e.g. Nearby Share, Smart Lock, Fast Pair, etc.
 // This flag is used to disable Cross-Device on platforms where we cannot yet
 // guarantee a good experience with the stock Bluetooth hardware (e.g. Reven /
-// ChromeOS Flex).
+// ChromeOS Flex). Access through IsCrossDeviceFeatureSuiteAllowed().
 BASE_FEATURE(kAllowCrossDeviceFeatureSuite,
              "AllowCrossDeviceFeatureSuite",
-#if BUILDFLAG(IS_REVEN)
-             base::FEATURE_DISABLED_BY_DEFAULT
-#else
-             base::FEATURE_ENABLED_BY_DEFAULT
-#endif  // BUILDFLAG(IS_REVEN)
-);
+             base::FEATURE_ENABLED_BY_DEFAULT);
 
 // Allows DevTools to open from the context menu and shortcut keys in Ash if
 // Lacros is the only browser.
@@ -3497,6 +3492,14 @@ bool IsCrosPrivacyHubLocationEnabled() {
   return base::FeatureList::IsEnabled(kCrosPrivacyHub);
 }
 
+bool IsCrossDeviceFeatureSuiteAllowed() {
+  if (switches::IsRevenBranding()) {
+    return false;
+  }
+
+  return base::FeatureList::IsEnabled(kAllowCrossDeviceFeatureSuite);
+}
+
 bool IsDeskButtonEnabled() {
   return base::FeatureList::IsEnabled(kDeskButton);
 }
@@ -4239,16 +4242,13 @@ bool IsOobeLazyLoadingEnabled() {
 }
 
 bool IsOobeQuickStartEnabled() {
-  if (switches::IsRevenBranding()) {
-    return false;
-  }
-
   // QuickStart directly depends on the 'Local Password' feature.
   if (!base::FeatureList::IsEnabled(kLocalPasswordForConsumers)) {
     return false;
   }
 
-  return base::FeatureList::IsEnabled(kOobeQuickStart);
+  return IsCrossDeviceFeatureSuiteAllowed() &&
+         base::FeatureList::IsEnabled(kOobeQuickStart);
 }
 
 bool IsOobeQuickStartOnLoginScreenEnabled() {

ash/constants/ash_features.h

@@ -1052,6 +1052,7 @@ COMPONENT_EXPORT(ASH_CONSTANTS) bool IsCopyClientKeysCertsToChapsEnabled();
 COMPONENT_EXPORT(ASH_CONSTANTS) bool IsCrosPrivacyHubAppPermissionsEnabled();
 COMPONENT_EXPORT(ASH_CONSTANTS) bool IsCrosPrivacyHubAppPermissionsV2Enabled();
 COMPONENT_EXPORT(ASH_CONSTANTS) bool IsCrosPrivacyHubLocationEnabled();
+COMPONENT_EXPORT(ASH_CONSTANTS) bool IsCrossDeviceFeatureSuiteAllowed();
 COMPONENT_EXPORT(ASH_CONSTANTS)
 bool IsCryptauthAttestationSyncingEnabled();
 COMPONENT_EXPORT(ASH_CONSTANTS) bool IsDeepLinkingEnabled();

ash/quick_pair/feature_status_tracker/fast_pair_support_utils.cc

@@ -12,7 +12,7 @@ namespace ash {
 namespace quick_pair {
 
 bool HasHardwareSupport(scoped_refptr<device::BluetoothAdapter> adapter) {
-  if (!base::FeatureList::IsEnabled(features::kAllowCrossDeviceFeatureSuite)) {
+  if (!features::IsCrossDeviceFeatureSuiteAllowed()) {
     return false;
   }
 

ash/shell.cc

@@ -1256,9 +1256,11 @@ void Shell::Init(
       std::make_unique<PolicyRecommendationRestorer>();
   screen_switch_check_controller_ =
       std::make_unique<ScreenSwitchCheckController>();
-  multidevice_notification_presenter_ =
-      std::make_unique<MultiDeviceNotificationPresenter>(
-          message_center::MessageCenter::Get());
+  if (features::IsCrossDeviceFeatureSuiteAllowed()) {
+    multidevice_notification_presenter_ =
+        std::make_unique<MultiDeviceNotificationPresenter>(
+            message_center::MessageCenter::Get());
+  }
   media_controller_ = std::make_unique<MediaControllerImpl>();
   media_notification_provider_ =
       shell_delegate_->CreateMediaNotificationProvider();

chrome/browser/nearby_sharing/nearby_sharing_service_factory.cc

@@ -56,8 +56,7 @@ bool NearbySharingServiceFactory::IsNearbyShareSupportedForBrowserContext(
     return *IsSupportedTesting();
   }
 
-  if (!base::FeatureList::IsEnabled(
-          ash::features::kAllowCrossDeviceFeatureSuite)) {
+  if (!ash::features::IsCrossDeviceFeatureSuiteAllowed()) {
     return false;
   }
 

chrome/browser/ui/webui/ash/settings/pages/bluetooth/bluetooth_section.cc

@@ -468,8 +468,7 @@ void BluetoothSection::UpdateSearchTags() {
   updater.AddSearchTags(GetBluetoothSearchConcepts());
 
   if (features::IsFastPairEnabled() &&
-      base::FeatureList::IsEnabled(
-          ash::features::kAllowCrossDeviceFeatureSuite)) {
+      features::IsCrossDeviceFeatureSuiteAllowed()) {
     if (pref_service_->GetBoolean(ash::prefs::kFastPairEnabled)) {
       updater.AddSearchTags(GetFastPairOnSearchConcepts());
     } else {

chrome/browser/ui/webui/ash/settings/pages/multidevice/multidevice_section.cc

@@ -751,8 +751,7 @@ void MultiDeviceSection::AddLoadTimeData(
           GetHelpUrlWithBoard(phonehub::kPhoneHubLearnMoreLink)));
 
   html_source->AddBoolean("isCrossDeviceFeatureSuiteEnabled",
-                          base::FeatureList::IsEnabled(
-                              ash::features::kAllowCrossDeviceFeatureSuite));
+                          features::IsCrossDeviceFeatureSuiteAllowed());
 
   // We still need to register strings even if Nearby Share is not supported.
   // For example, the HTML is always built but only displayed if Nearby Share is
@@ -891,8 +890,7 @@ void MultiDeviceSection::OnHostStatusChanged(
   updater.RemoveSearchTags(GetMultiDeviceOptedOutSearchConcepts());
   updater.RemoveSearchTags(GetMultiDeviceOptedInSearchConcepts());
 
-  if (!base::FeatureList::IsEnabled(
-          ash::features::kAllowCrossDeviceFeatureSuite)) {
+  if (!features::IsCrossDeviceFeatureSuiteAllowed()) {
     // Do not add multidevice search tags if Cross Device is disabled.
     return;
   }
@@ -914,8 +912,7 @@ void MultiDeviceSection::OnFeatureStatesChanged(
   updater.RemoveSearchTags(GetMultiDeviceOptedInWifiSyncSearchConcepts());
   updater.RemoveSearchTags(GetMultiDeviceOptedInPhoneHubAppsSearchConcepts());
 
-  if (!base::FeatureList::IsEnabled(
-          ash::features::kAllowCrossDeviceFeatureSuite)) {
+  if (!features::IsCrossDeviceFeatureSuiteAllowed()) {
     // Do not add multidevice search tags if Cross Device is disabled.
     return;
   }

chromeos/ash/services/multidevice_setup/feature_state_manager_impl.cc

@@ -398,7 +398,7 @@ bool FeatureStateManagerImpl::IsAllowedByPolicy(mojom::Feature feature) {
 }
 
 bool FeatureStateManagerImpl::IsSupportedByChromebook(mojom::Feature feature) {
-  if (!base::FeatureList::IsEnabled(features::kAllowCrossDeviceFeatureSuite)) {
+  if (!features::IsCrossDeviceFeatureSuiteAllowed()) {
     return false;
   }