diff -r 000000000000 -r 6474c204b198 dom/telephony/test/marionette/test_call_mute.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/telephony/test/marionette/test_call_mute.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+MARIONETTE_TIMEOUT = 60000;
+MARIONETTE_HEAD_JS = 'head.js';
+
+function test_call_mute() {
+  telephony.muted = true;
+  is(telephony.muted, true);
+  telephony.muted = false;
+  is(telephony.muted, false);
+  cleanUp();
+}
+
+function cleanUp() {
+  finish();
+}
+
+startTest(function() {
+  test_call_mute();
+});