[Android][Settings] Disable Phone as a Security Key fragment

PAASK settings fragment has been long there, not working as expected.
It seems like it has been replaced by Google Play Services'
"Passkey-linked devices" settings, and it actually works.

Removing the PAASK entry from Chrome settings behind a feature flag is
the right choice here. Linking is not handled by Chrome anymore, and it
is on its way to deprecation too (crbug.com/372493822)

Bug: 377475533
Change-Id: I75581c419d4271e10ae3c68a95e7e51e9226b8b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6017947
Reviewed-by: Nina Satragno <nsatragno@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Commit-Queue: Adem Derinel <derinel@google.com>
Cr-Commit-Position: refs/heads/main@{#1382883}

chrome/android/java/src/org/chromium/chrome/browser/privacy/settings/PrivacySettings.java

@@ -52,6 +52,8 @@ import org.chromium.components.browser_ui.util.TraceEventVectorDrawableCompat;
 import org.chromium.components.content_settings.CookieControlsMode;
 import org.chromium.components.signin.identitymanager.ConsentLevel;
 import org.chromium.components.user_prefs.UserPrefs;
+import org.chromium.device.DeviceFeatureList;
+import org.chromium.device.DeviceFeatureMap;
 import org.chromium.ui.text.SpanApplier;
 
 /** Fragment to keep track of the all the privacy related preferences. */
@@ -67,6 +69,7 @@ public class PrivacySettings extends ChromeBaseSettingsFragment
     private static final String PREF_PRIVACY_SANDBOX = "privacy_sandbox";
     private static final String PREF_PRIVACY_GUIDE = "privacy_guide";
     private static final String PREF_INCOGNITO_LOCK = "incognito_lock";
+    private static final String PREF_PHONE_AS_A_SECURITY_KEY = "phone_as_a_security_key";
     @VisibleForTesting static final String PREF_CLEAR_BROWSING_DATA = "clear_browsing_data";
     @VisibleForTesting static final String PREF_DO_NOT_TRACK = "do_not_track";
     @VisibleForTesting static final String PREF_FP_PROTECTION = "fp_protection";
@@ -229,6 +232,10 @@ public class PrivacySettings extends ChromeBaseSettingsFragment
             clearBrowsingDataAdvancedPreference.setVisible(true);
         }
 
+        Preference phoneAsASecurityKey = findPreference(PREF_PHONE_AS_A_SECURITY_KEY);
+        phoneAsASecurityKey.setVisible(
+                DeviceFeatureMap.isEnabled(DeviceFeatureList.WEBAUTHN_ENABLE_PAASK_SETTING));
+
         updatePreferences();
     }
 

device/fido/features.cc

@@ -53,6 +53,12 @@ BASE_FEATURE(kWebAuthnAndroidCredMan,
 BASE_FEATURE(kWebAuthnAndroidUsePasskeyCache,
              "WebAuthenticationAndroidUsePasskeyCache",
              base::FEATURE_ENABLED_BY_DEFAULT);
+
+// This is a deprecation flag for "Phone as a security key" privacy settings
+// fragment. Disabled in M133, remove in or after M136.
+BASE_FEATURE(kWebAuthnEnablePaaskFragment,
+             "WebAuthenticationEnablePaaskFragment",
+             base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_ANDROID)
 
 // Enabled in M118. Remove in or after M121.

device/fido/features.h

@@ -42,6 +42,11 @@ inline constexpr base::FeatureParam<bool> kWebAuthnAndroidGpmInCredMan{
 // passkeys from GMSCore. This is for comparison only.
 COMPONENT_EXPORT(DEVICE_FIDO)
 BASE_DECLARE_FEATURE(kWebAuthnAndroidUsePasskeyCache);
+
+// Enable the "Phone as a security key" fragment in Privacy Settings. This flag
+// is now handled by Gmscore, in Android Settings > "Passkey-linked devices".
+COMPONENT_EXPORT(DEVICE_FIDO)
+BASE_DECLARE_FEATURE(kWebAuthnEnablePaaskFragment);
 #endif  // BUILDFLAG(IS_ANDROID)
 
 // These five feature flags control whether iCloud Keychain is the default

services/device/public/cpp/device_feature_map.cc

@@ -24,6 +24,7 @@ namespace {
 const base::Feature* const kFeaturesExposedToJava[] = {
     &device::kWebAuthnAndroidCredMan,
     &device::kWebAuthnAndroidUsePasskeyCache,
+    &device::kWebAuthnEnablePaaskFragment,
     &kGenericSensorExtraClasses,
     &kBatteryStatusManagerBroadcastReceiverInBackground,
 };

services/device/public/java/src/org/chromium/device/DeviceFeatureList.java

@@ -20,4 +20,6 @@ public abstract class DeviceFeatureList {
             "WebAuthenticationAndroidUsePasskeyCache";
     public static final String BATTERY_STATUS_MANAGER_BROADCAST_RECEIVER_IN_BACKGROUND =
             "BatteryStatusManagerBroadcastReceiverInBackground";
+    public static final String WEBAUTHN_ENABLE_PAASK_SETTING =
+            "WebAuthenticationEnablePaaskFragment";
 }