BB 42027: Base Browser migration procedures.

This commit implmenents the the Base Browser's version of _migrateUI.

browser/components/BrowserGlue.sys.mjs

@@ -1593,6 +1593,9 @@ BrowserGlue.prototype = {
     // handle any UI migration
     this._migrateUI();
 
+    // Base Browser-specific version of _migrateUI.
+    this._migrateUIBB();
+
     if (!Services.prefs.prefHasUserValue(PREF_PDFJS_ISDEFAULT_CACHE_STATE)) {
       lazy.PdfJs.checkIsDefault(this._isNewProfile);
     }
@@ -4719,6 +4722,51 @@ BrowserGlue.prototype = {
     Services.prefs.setIntPref("browser.migration.version", UI_VERSION);
   },
 
+  _migrateUIBB() {
+    // Version 1: 13.0a3. Reset layout.css.prefers-color-scheme.content-override
+    //            for tor-browser#41739.
+    // Version 2: 14.0a5: Reset the privacy tracking headers preferences since
+    //            the UI is hidden. tor-browser#42777.
+    //            Also, do not set
+    //            dom.security.https_only_mode_send_http_background_request in
+    //            the security level anymore (tor-browser#42149).
+    //            Also, reset security.xfocsp.errorReporting.automatic since we
+    //            hid its neterror checkbox. tor-browser#42653.
+    // Version 3: 14.0a7: Reset general.smoothScroll. tor-browser#42070.
+    const MIGRATION_VERSION = 3;
+    const MIGRATION_PREF = "basebrowser.migration.version";
+    // We do not care whether this is a new or old profile, since in version 1
+    // we just quickly clear a user preference, which should not do anything to
+    // new profiles.
+    // Shall we ever raise the version number and have a watershed, we can add
+    // a check easily (any version > 0 will be an old profile).
+    const currentVersion = Services.prefs.getIntPref(MIGRATION_PREF, 0);
+    if (currentVersion < 1) {
+      Services.prefs.clearUserPref(
+        "layout.css.prefers-color-scheme.content-override"
+      );
+    }
+    if (currentVersion < 2) {
+      for (const prefName of [
+        "privacy.globalprivacycontrol.enabled",
+        "privacy.donottrackheader.enabled",
+        // Telemetry preference for if the user changed the value.
+        "privacy.globalprivacycontrol.was_ever_enabled",
+        // The next two preferences have no corresponding UI, but are related.
+        "privacy.globalprivacycontrol.functionality.enabled",
+        "privacy.globalprivacycontrol.pbmode.enabled",
+        "dom.security.https_only_mode_send_http_background_request",
+        "security.xfocsp.errorReporting.automatic",
+      ]) {
+        Services.prefs.clearUserPref(prefName);
+      }
+    }
+    if (currentVersion < 3) {
+      Services.prefs.clearUserPref("general.smoothScroll");
+    }
+    Services.prefs.setIntPref(MIGRATION_PREF, MIGRATION_VERSION);
+  },
+
   async _showUpgradeDialog() {
     const data = await lazy.OnboardingMessageProvider.getUpgradeMessage();
     const { gBrowser } = lazy.BrowserWindowTracker.getTopWindow();

mobile/shared/components/geckoview/GeckoViewStartup.sys.mjs

@@ -259,6 +259,8 @@ export class GeckoViewStartup {
           "GeckoView:InitialForeground",
         ]);
 
+        this.#migratePreferences();
+
         Services.obs.addObserver(this, "browser-idle-startup-tasks-finished");
         Services.obs.addObserver(this, "handlersvc-store-initialized");
 
@@ -365,6 +367,50 @@ export class GeckoViewStartup {
         break;
     }
   }
+
+  /**
+   * This is the equivalent of BrowserGlue._migrateUITBB.
+   */
+  #migratePreferences() {
+    const MIGRATION_VERSION = 1;
+    const MIGRATION_PREF = "torbrowser.migration_android.version";
+
+    // We do not have a way to check for new profiles on Android.
+    // However, the first version is harmless for new installs, so run it
+    // anyway.
+    const currentVersion = Services.prefs.getIntPref(MIGRATION_PREF, 0);
+    if (currentVersion < 1) {
+      // First implementation of the migration on Android (tor-browser#43124,
+      // 14.0a5, September 2024).
+      const prefToClear = [
+        // Old torbutton preferences not used anymore.
+        // Some of them should have never been set on Android, as on Android we
+        // force PBM... But who knows about very old profiles.
+        "browser.cache.disk.enable",
+        "places.history.enabled",
+        "security.nocertdb",
+        "permissions.memory_only",
+        "extensions.torbutton.loglevel",
+        "extensions.torbutton.logmethod",
+        "extensions.torbutton.pref_fixup_version",
+        "extensions.torbutton.resize_new_windows",
+        "extensions.torbutton.startup",
+        "extensions.torlauncher.prompt_for_locale",
+        "extensions.torlauncher.loglevel",
+        "extensions.torlauncher.logmethod",
+        "extensions.torlauncher.torrc_fixup_version",
+        // tor-browser#42149: Do not change HTTPS-Only settings in the security
+        // level.
+        "dom.security.https_only_mode_send_http_background_request",
+      ];
+      for (const pref of prefToClear) {
+        if (Services.prefs.prefHasUserValue(pref)) {
+          Services.prefs.clearUserPref(pref);
+        }
+      }
+    }
+    Services.prefs.setIntPref(MIGRATION_PREF, MIGRATION_VERSION);
+  }
 }
 
 GeckoViewStartup.prototype.classID = Components.ID(