feat(privacy): Use Content Settings for some Shields Settings on iOS (#30608)

* Add feature flag
- Add an iOS-only feature flag for using content settings for persisting Brave Shields settings.

* Update Shields default/global settings.
- Use content settings when the feature flag is enabled for default settings.

* Use content settings for shields when flag is enabled.
- Update BraveShieldsTabHelper to use content settings when the flag is enabled.

* Use core P3A when feature flag is enabled.

components/brave_shields/core/common/features.cc

@@ -105,6 +105,10 @@ BASE_FEATURE(kBraveShredCacheData,
 #else
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif
+// When enabled, brave will use content settings for Shields on iOS.
+BASE_FEATURE(kBraveShieldsContentSettingsIOS,
+             "BraveShieldsContentSettingsIOS",
+             base::FEATURE_DISABLED_BY_DEFAULT);
 // When enabled, will display debug menu for adblock features in the Shields
 // panel.
 BASE_FEATURE(kBraveIOSDebugAdblock,

components/brave_shields/core/common/features.h

@@ -34,6 +34,7 @@ BASE_DECLARE_FEATURE(kBraveLocalhostAccessPermission);
 BASE_DECLARE_FEATURE(kBraveReduceLanguage);
 BASE_DECLARE_FEATURE(kBraveShredFeature);
 BASE_DECLARE_FEATURE(kBraveShredCacheData);
+BASE_DECLARE_FEATURE(kBraveShieldsContentSettingsIOS);
 BASE_DECLARE_FEATURE(kBraveIOSDebugAdblock);
 BASE_DECLARE_FEATURE(kBraveIOSEnableFarblingPlugins);
 BASE_DECLARE_FEATURE(kBraveShowStrictFingerprintingMode);

ios/brave-ios/Sources/Brave/Frontend/Browser/BrowserViewController/BVC+P3A.swift

@@ -158,6 +158,8 @@ extension BrowserViewController {
   }
 
   @MainActor private func recordShieldsLevelUpdateP3A(buckets: [Bucket]) {
+    // if the flag is enabled, P3A is recorded in core shields functions.
+    guard FeatureList.kBraveShieldsContentSettings.enabled else { return }
     // Q51 On how many domains has the user set the adblock setting to be lower (block less) than the default?
     let adsBelowGlobalCount = Domain.totalDomainsWithAdblockShieldsLoweredFromGlobal()
     UmaHistogramRecordValueToBucket(
@@ -175,6 +177,8 @@ extension BrowserViewController {
   }
 
   func recordFinterprintProtectionP3A(buckets: [Bucket]) {
+    // if the flag is enabled, P3A is recorded in core shields functions.
+    guard FeatureList.kBraveShieldsContentSettings.enabled else { return }
     // Q53 On how many domains has the user set the FP setting to be lower (block less) than the default?
     let fingerprintingBelowGlobalCount =
       Domain.totalDomainsWithFingerprintingProtectionLoweredFromGlobal()
@@ -194,6 +198,8 @@ extension BrowserViewController {
   }
 
   func recordGlobalAdBlockShieldsP3A() {
+    // if the flag is enabled, P3A is recorded in core shields functions.
+    guard FeatureList.kBraveShieldsContentSettings.enabled else { return }
     // Q46 What is the global ad blocking shields setting?
     enum Answer: Int, CaseIterable {
       case disabled = 0
@@ -213,6 +219,8 @@ extension BrowserViewController {
   }
 
   func recordGlobalFingerprintingShieldsP3A() {
+    // if the flag is enabled, P3A is recorded in core shields functions.
+    guard FeatureList.kBraveShieldsContentSettings.enabled else { return }
     // Q47 What is the global fingerprinting shields setting?
     enum Answer: Int, CaseIterable {
       case disabled = 0

ios/brave-ios/Sources/Brave/Frontend/Browser/BrowserViewController/BVC+TabManagerDelegate.swift

@@ -30,7 +30,12 @@ extension BrowserViewController: TabManagerDelegate {
     tab.pageMetadataHelper = .init(tab: tab)
     tab.faviconTabHelper = .init(tab: tab)
     tab.userActivityHelper = .init(tab: tab)
-    let braveShieldsHelper: BraveShieldsTabHelper = .init(tab: tab)
+    let profile =
+      tab.isPrivate ? profileController.profile.offTheRecordProfile : profileController.profile
+    let braveShieldsHelper: BraveShieldsTabHelper = .init(
+      tab: tab,
+      braveShieldsSettings: BraveShieldsSettingsFactory.create(for: profile)
+    )
     tab.braveShieldsHelper = braveShieldsHelper
     // When `BraveShieldsTabHelper+TabPolicyDecider` is moved to `BraveShields` target,
     // we should add it as a policy decider at initialization.

ios/brave-ios/Sources/Brave/Frontend/Browser/BrowserViewController/BVC+ToolbarDelegate.swift

@@ -520,6 +520,7 @@ extension BrowserViewController: TopToolbarDelegate {
           tabManager: self.tabManager,
           feedDataSource: self.feedDataSource,
           debounceService: DebounceServiceFactory.get(privateMode: false),
+          braveShieldsSettings: BraveShieldsSettingsFactory.create(for: profileController.profile),
           braveCore: profileController,
           p3aUtils: braveCore.p3aUtils,
           rewards: rewards,

ios/brave-ios/Sources/Brave/Frontend/Browser/LinkPreviewViewController.swift

@@ -2,6 +2,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+import BraveCore
 import BraveShields
 import Data
 import Shared
@@ -42,7 +43,14 @@ class LinkPreviewViewController: UIViewController {
     tab.miscDelegate = browserController
     tab.createWebView()
     tab.addPolicyDecider(browserController)
-    let braveShieldsTabHelper: BraveShieldsTabHelper = .init(tab: tab)
+    let profile =
+      tab.isPrivate
+      ? browserController.profileController.profile.offTheRecordProfile
+      : browserController.profileController.profile
+    let braveShieldsTabHelper: BraveShieldsTabHelper = .init(
+      tab: tab,
+      braveShieldsSettings: BraveShieldsSettingsFactory.create(for: profile)
+    )
     tab.braveShieldsHelper = braveShieldsTabHelper
     tab.addPolicyDecider(braveShieldsTabHelper)
     tab.delegate = browserController

ios/brave-ios/Sources/Brave/Frontend/Browser/TabManager.swift

@@ -1262,7 +1262,7 @@ class TabManager: NSObject {
       } else {
         // Don't access `shredLevel` directly, but `TabState` is unavailable
         // to access via `BraveShieldsTabHelper`. Temporarily access here until
-        // we switch to using `BraveShieldsUtilsIOS` with brave-browser#47350
+        // we switch to using `BraveShieldsSettings` with brave-browser#47350
         let siteDomain = Domain.getOrCreate(
           forUrl: url,
           persistent: !isPrivate

ios/brave-ios/Sources/Brave/Frontend/Settings/Features/ShieldsPrivacy/AdvancedShieldSettings.swift

@@ -65,9 +65,35 @@ import os
   }
   @Published var adBlockAndTrackingPreventionLevel: ShieldLevel {
     didSet {
+      guard oldValue != adBlockAndTrackingPreventionLevel else { return }
+      if FeatureList.kBraveShieldsContentSettings.enabled {
+        braveShieldsSettings.defaultAdBlockMode = adBlockAndTrackingPreventionLevel.adBlockMode
+      }
+      // Also assign to existing pref until deprecated so reverse migration is not required
       ShieldPreferences.blockAdsAndTrackingLevel = adBlockAndTrackingPreventionLevel
     }
   }
+  @Published var isBlockScriptsEnabled: Bool {
+    didSet {
+      guard oldValue != isBlockScriptsEnabled else { return }
+      if FeatureList.kBraveShieldsContentSettings.enabled {
+        braveShieldsSettings.isBlockScriptsEnabledByDefault = isBlockScriptsEnabled
+      }
+      // Also assign to existing pref until deprecated so reverse migration is not required
+      Preferences.Shields.blockScripts.value = isBlockScriptsEnabled
+    }
+  }
+  @Published var isBlockFingerprintingEnabled: Bool {
+    didSet {
+      guard oldValue != isBlockFingerprintingEnabled else { return }
+      if FeatureList.kBraveShieldsContentSettings.enabled {
+        braveShieldsSettings.defaultFingerprintMode =
+          isBlockFingerprintingEnabled ? .standardMode : .allowMode
+      }
+      // Also assign to existing pref until deprecated so reverse migration is not required
+      Preferences.Shields.fingerprintingProtection.value = isBlockFingerprintingEnabled
+    }
+  }
   @Published var httpsUpgradeLevel: HTTPSUpgradeLevel {
     didSet {
       ShieldPreferences.httpsUpgradeLevel = httpsUpgradeLevel
@@ -79,6 +105,7 @@ import os
   }
   @Published var shredLevel: SiteShredLevel {
     didSet {
+      // TODO: Support AutoShred via content settings brave-browser#47753
       ShieldPreferences.shredLevel = shredLevel
     }
   }
@@ -107,6 +134,7 @@ import os
   private let p3aUtilities: BraveP3AUtils
   private let deAmpPrefs: DeAmpPrefs
   private let debounceService: (any DebounceService)?
+  private let braveShieldsSettings: any BraveShieldsSettings
   private let rewards: BraveRewards?
   private let clearDataCallback: ClearDataCallback
   private let webcompatReporterHandler: WebcompatReporterWebcompatReporterHandler?
@@ -117,6 +145,7 @@ import os
     tabManager: TabManager,
     feedDataSource: FeedDataSource,
     debounceService: (any DebounceService)?,
+    braveShieldsSettings: any BraveShieldsSettings,
     braveCore: BraveProfileController,
     p3aUtils: BraveP3AUtils,
     rewards: BraveRewards?,
@@ -126,14 +155,25 @@ import os
     self.p3aUtilities = p3aUtils
     self.deAmpPrefs = braveCore.deAmpPrefs
     self.debounceService = debounceService
+    self.braveShieldsSettings = braveShieldsSettings
     self.tabManager = tabManager
     self.isP3AEnabled = p3aUtilities.isP3AEnabled
     self.rewards = rewards
     self.clearDataCallback = clearDataCallback
-    self.adBlockAndTrackingPreventionLevel = ShieldPreferences.blockAdsAndTrackingLevel
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      self.adBlockAndTrackingPreventionLevel = braveShieldsSettings.defaultAdBlockMode.shieldLevel
+      self.isBlockScriptsEnabled = braveShieldsSettings.isBlockScriptsEnabledByDefault
+      self.isBlockFingerprintingEnabled =
+        braveShieldsSettings.defaultFingerprintMode == .standardMode
+    } else {
+      self.adBlockAndTrackingPreventionLevel = ShieldPreferences.blockAdsAndTrackingLevel
+      self.isBlockScriptsEnabled = Preferences.Shields.blockScripts.value
+      self.isBlockFingerprintingEnabled = Preferences.Shields.fingerprintingProtection.value
+    }
     self.httpsUpgradeLevel = ShieldPreferences.httpsUpgradeLevel
     self.isDeAmpEnabled = deAmpPrefs.isDeAmpEnabled
     self.isDebounceEnabled = debounceService?.isEnabled ?? false
+    // TODO: Support AutoShred via content settings brave-browser#47753
     self.shredLevel = ShieldPreferences.shredLevel
     self.webcompatReporterHandler = webcompatReporterHandler
     self.isSurveyPanelistEnabled = rewards?.ads.isSurveyPanelistEnabled ?? false

ios/brave-ios/Sources/Brave/Frontend/Settings/Features/ShieldsPrivacy/DefaultShieldsSectionView.swift

@@ -72,16 +72,16 @@ struct DefaultShieldsSectionView: View {
         subtitle: Strings.autoRedirectTrackingURLsDescription,
         toggle: $settings.isDebounceEnabled
       )
-      OptionToggleView(
+
+      ToggleView(
         title: Strings.blockScripts,
         subtitle: Strings.blockScriptsDescription,
-        option: Preferences.Shields.blockScripts
+        toggle: $settings.isBlockScriptsEnabled
       )
-
-      OptionToggleView(
+      ToggleView(
         title: Strings.fingerprintingProtection,
         subtitle: Strings.fingerprintingProtectionDescription,
-        option: Preferences.Shields.fingerprintingProtection
+        toggle: $settings.isBlockFingerprintingEnabled
       )
 
       ToggleView(

ios/brave-ios/Sources/Brave/Frontend/Settings/SettingsViewController.swift

@@ -364,6 +364,7 @@ class SettingsViewController: TableViewController {
                   tabManager: self.tabManager,
                   feedDataSource: self.feedDataSource,
                   debounceService: DebounceServiceFactory.get(privateMode: false),
+                  braveShieldsSettings: BraveShieldsSettingsFactory.create(for: braveCore.profile),
                   braveCore: braveCore,
                   p3aUtils: p3aUtilities,
                   rewards: rewards,

ios/brave-ios/Sources/BraveShields/BraveShieldsTabHelper.swift

@@ -3,6 +3,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+import BraveCore
 import Data
 import Foundation
 import Preferences
@@ -21,25 +22,40 @@ extension TabDataValues {
 @MainActor
 public class BraveShieldsTabHelper {
   private weak var tab: (any TabState)?
+  private let braveShieldsSettings: any BraveShieldsSettings
 
-  public init(tab: some TabState) {
+  public init(
+    tab: some TabState,
+    braveShieldsSettings: any BraveShieldsSettings
+  ) {
     self.tab = tab
+    self.braveShieldsSettings = braveShieldsSettings
   }
 
   public func isBraveShieldsEnabled(for url: URL?) -> Bool {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return false }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      return braveShieldsSettings.isBraveShieldsEnabled(for: url)
+    }
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     return !domain.areAllShieldsOff
   }
 
   public func setBraveShieldsEnabled(_ isEnabled: Bool, for url: URL?) {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      braveShieldsSettings.setBraveShieldsEnabled(isEnabled, for: url)
+    }
+    // Also assign to Domain until deprecated so reverse migration is required
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     domain.shield_allOff = NSNumber(booleanLiteral: !isEnabled)
   }
 
   public func shieldLevel(for url: URL?, considerAllShieldsOption: Bool) -> ShieldLevel {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return .disabled }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      return braveShieldsSettings.adBlockMode(for: url).shieldLevel
+    }
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     if considerAllShieldsOption {
       return domain.globalBlockAdsAndTrackingLevel
@@ -50,18 +66,30 @@ public class BraveShieldsTabHelper {
 
   public func setShieldLevel(_ shieldLevel: ShieldLevel, for url: URL?) {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      braveShieldsSettings.setAdBlockMode(shieldLevel.adBlockMode, for: url)
+    }
+    // Also assign to Domain until deprecated so reverse migration is required
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     domain.domainBlockAdsAndTrackingLevel = shieldLevel
   }
 
   public func setBlockScriptsEnabled(_ isEnabled: Bool, for url: URL?) {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      braveShieldsSettings.setBlockScriptsEnabled(isEnabled, for: url)
+    }
+    // Also assign to Domain until deprecated so reverse migration is required
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     domain.shield_noScript = NSNumber(booleanLiteral: isEnabled)
   }
 
   public func setBlockFingerprintingEnabled(_ isEnabled: Bool, for url: URL?) {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      braveShieldsSettings.setFingerprintMode(isEnabled ? .standardMode : .allowMode, for: url)
+    }
+    // Also assign to Domain until deprecated so reverse migration is required
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     domain.shield_fpProtection = NSNumber(booleanLiteral: isEnabled)
   }
@@ -73,6 +101,20 @@ public class BraveShieldsTabHelper {
     considerAllShieldsOption: Bool
   ) -> Bool {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return false }
+    if FeatureList.kBraveShieldsContentSettings.enabled {
+      if considerAllShieldsOption && !isBraveShieldsEnabled(for: url) {
+        // Shields is disabled for this url
+        return false
+      }
+      switch shield {
+      case .allOff:
+        return braveShieldsSettings.isBraveShieldsEnabled(for: url)
+      case .fpProtection:
+        return braveShieldsSettings.fingerprintMode(for: url) == .standardMode
+      case .noScript:
+        return braveShieldsSettings.isBlockScriptsEnabled(for: url)
+      }
+    }
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     return domain.isShieldExpected(shield, considerAllShieldsOption: considerAllShieldsOption)
   }
@@ -81,6 +123,7 @@ public class BraveShieldsTabHelper {
     for url: URL?
   ) -> SiteShredLevel {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return .never }
+    // TODO: Support AutoShred via content settings brave-browser#47753
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     return domain.shredLevel
   }
@@ -90,6 +133,7 @@ public class BraveShieldsTabHelper {
     for url: URL?
   ) {
     guard let url = url ?? tab?.visibleURL, let isPrivate = tab?.isPrivate else { return }
+    // TODO: Support AutoShred via content settings brave-browser#47753
     let domain = Domain.getOrCreate(forUrl: url, persistent: !isPrivate)
     domain.shredLevel = shredLevel
   }

ios/brave-ios/Sources/BraveShields/ShieldLevel.swift

@@ -3,6 +3,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+import BraveCore
 import Foundation
 
 /// A 3 part option for shield levels varying in strength of blocking content
@@ -37,4 +38,25 @@ public enum ShieldLevel: String, CaseIterable, Hashable {
     case .disabled, .standard: return false
     }
   }
+
+  public var adBlockMode: BraveShields.AdBlockMode {
+    switch self {
+    case .aggressive: return .aggressive
+    case .standard: return .standard
+    case .disabled: return .allow
+    }
+  }
+}
+
+extension BraveShields.AdBlockMode {
+  public var shieldLevel: ShieldLevel {
+    switch self {
+    case .aggressive: return .aggressive
+    case .standard: return .standard
+    case .allow: return .disabled
+    @unknown default:
+      assertionFailure("Unexpected AdBlockMode")
+      return .standard
+    }
+  }
 }

ios/browser/api/features/features.h

@@ -53,6 +53,7 @@ OBJC_EXPORT
 @property(class, nonatomic, readonly) Feature* kBraveSearchDefaultAPIFeature;
 @property(class, nonatomic, readonly) Feature* kBraveShredFeature;
 @property(class, nonatomic, readonly) Feature* kBraveShredCacheData;
+@property(class, nonatomic, readonly) Feature* kBraveShieldsContentSettings;
 @property(class, nonatomic, readonly) Feature* kBraveIOSDebugAdblock;
 @property(class, nonatomic, readonly) Feature* kBraveIOSEnableFarblingPlugins;
 @property(class, nonatomic, readonly)

ios/browser/api/features/features.mm

@@ -211,6 +211,11 @@
       initWithFeature:&brave_shields::features::kBraveShredCacheData];
 }
 
++ (Feature*)kBraveShieldsContentSettings {
+  return [[Feature alloc] initWithFeature:&brave_shields::features::
+                                              kBraveShieldsContentSettingsIOS];
+}
+
 + (Feature*)kBraveIOSDebugAdblock {
   return [[Feature alloc]
       initWithFeature:&brave_shields::features::kBraveIOSDebugAdblock];

ios/browser/flags/about_flags.mm

@@ -90,6 +90,15 @@
           flags_ui::kOsIos,                                                    \
           FEATURE_VALUE_TYPE(brave_shields::features::kBraveShredCacheData),   \
       },                                                                       \
+      {                                                                        \
+          "brave-shields-content-settings",                                    \
+          "Brave Shields use Content Settings",                                \
+          "Brave Shields will use content settings for persisting Shields "    \
+          "preferences",                                                       \
+          flags_ui::kOsIos,                                                    \
+          FEATURE_VALUE_TYPE(                                                  \
+              brave_shields::features::kBraveShieldsContentSettingsIOS),       \
+      },                                                                       \
       {                                                                        \
           "https-by-default",                                                  \
           "Use HTTPS by Default",                                              \