1 files changed, 19 insertions, 0 deletions
diff --git a/browser/modules/TransientPrefs.sys.mjs b/browser/modules/TransientPrefs.sys.mjs
new file mode 100644
index 0000000000..b9a66ca5cd
--- /dev/null
+++ b/browser/modules/TransientPrefs.sys.mjs
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+var prefVisibility = new Map();
+
+/* Use for preferences that should only be visible when they've been modified.
+   When reset to their default state, they remain visible until restarting the
+   application. */
+
+export var TransientPrefs = {
+  prefShouldBeVisible(prefName) {
+    if (Services.prefs.prefHasUserValue(prefName)) {
+      prefVisibility.set(prefName, true);
+    }
+
+    return !!prefVisibility.get(prefName);
+  },
+};