1 files changed, 34 insertions, 0 deletions
diff --git a/browser/actors/RFPHelperParent.jsm b/browser/actors/RFPHelperParent.jsm
new file mode 100644
index 0000000000..481e2fd99b
--- /dev/null
+++ b/browser/actors/RFPHelperParent.jsm
@@ -0,0 +1,34 @@
+1; /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* 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 EXPORTED_SYMBOLS = ["RFPHelperParent"];
+
+const { XPCOMUtils } = ChromeUtils.importESModule(
+  "resource://gre/modules/XPCOMUtils.sys.mjs"
+);
+
+const kPrefLetterboxing = "privacy.resistFingerprinting.letterboxing";
+
+const lazy = {};
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "isLetterboxingEnabled",
+  kPrefLetterboxing,
+  false
+);
+
+class RFPHelperParent extends JSWindowActorParent {
+  receiveMessage(aMessage) {
+    if (
+      lazy.isLetterboxingEnabled &&
+      aMessage.name == "Letterboxing:ContentSizeUpdated"
+    ) {
+      let browser = this.browsingContext.top.embedderElement;
+      let window = browser.ownerGlobal;
+      window.RFPHelper.contentSizeUpdated(window);
+    }
+  }
+}