--- a/browser/locales/en-US/chrome/browser/sitePermissions.properties
+++ b/browser/locales/en-US/chrome/browser/sitePermissions.properties
@@ -23,16 +23,17 @@ state.current.hide = Hide Prompt
 #                    state.multichoice.allowForSession,
 #                    state.multichoice.block):
 # Used to label permission state checkboxes in the page info dialog.
 state.multichoice.alwaysAsk = Always Ask
 state.multichoice.allow = Allow
 state.multichoice.allowForSession = Allow for Session
 state.multichoice.block = Block
 
+permission.autoplay-media.label = Automatically Play Media with Sound
 permission.cookie.label = Set Cookies
 permission.desktop-notification2.label = Receive Notifications
 permission.image.label = Load Images
 permission.camera.label = Use the Camera
 permission.microphone.label = Use the Microphone
 permission.screen.label = Share the Screen
 permission.install.label = Install Add-ons
 permission.popup.label = Open Pop-up Windows

--- a/browser/modules/test/unit/test_SitePermissions.js
+++ b/browser/modules/test/unit/test_SitePermissions.js
@@ -5,17 +5,17 @@
 
 ChromeUtils.import("resource:///modules/SitePermissions.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 const RESIST_FINGERPRINTING_ENABLED = Services.prefs.getBoolPref("privacy.resistFingerprinting");
 const MIDI_ENABLED = Services.prefs.getBoolPref("dom.webmidi.enabled");
 
 add_task(async function testPermissionsListing() {
-  let expectedPermissions = ["camera", "cookie", "desktop-notification", "focus-tab-by-prompt",
+  let expectedPermissions = ["autoplay-media", "camera", "cookie", "desktop-notification", "focus-tab-by-prompt",
      "geo", "image", "install", "microphone", "plugin:flash", "popup", "screen", "shortcuts",
      "persistent-storage"];
   if (RESIST_FINGERPRINTING_ENABLED) {
     // Canvas permission should be hidden unless privacy.resistFingerprinting
     // is true.
     expectedPermissions.push("canvas");
   }
   if (MIDI_ENABLED) {
@@ -101,17 +101,17 @@ add_task(async function testGetAvailable
                    [ SitePermissions.ALLOW,
                      SitePermissions.BLOCK ]);
 });
 
 add_task(async function testExactHostMatch() {
   let uri = Services.io.newURI("https://example.com");
   let subUri = Services.io.newURI("https://test1.example.com");
 
-  let exactHostMatched = ["desktop-notification", "focus-tab-by-prompt", "camera",
+  let exactHostMatched = ["autoplay-media", "desktop-notification", "focus-tab-by-prompt", "camera",
                           "microphone", "screen", "geo", "persistent-storage"];
   if (RESIST_FINGERPRINTING_ENABLED) {
     // Canvas permission should be hidden unless privacy.resistFingerprinting
     // is true.
     exactHostMatched.push("canvas");
   }
   if (MIDI_ENABLED) {
     // WebMIDI is only pref'd on in nightly.
@@ -122,17 +122,17 @@ add_task(async function testExactHostMat
   let nonExactHostMatched = ["image", "cookie", "plugin:flash", "popup", "install", "shortcuts"];
 
   let permissions = SitePermissions.listPermissions();
   for (let permission of permissions) {
     SitePermissions.set(uri, permission, SitePermissions.ALLOW);
 
     if (exactHostMatched.includes(permission)) {
       // Check that the sub-origin does not inherit the permission from its parent.
-      Assert.equal(SitePermissions.get(subUri, permission).state, SitePermissions.UNKNOWN,
+      Assert.equal(SitePermissions.get(subUri, permission).state, SitePermissions.getDefault(permission),
         `${permission} should exact-host match`);
     } else if (nonExactHostMatched.includes(permission)) {
       // Check that the sub-origin does inherit the permission from its parent.
       Assert.equal(SitePermissions.get(subUri, permission).state, SitePermissions.ALLOW,
         `${permission} should not exact-host match`);
     } else {
       Assert.ok(false, `Found an unknown permission ${permission} in exact host match test.` +
                        "Please add new permissions from SitePermissions.jsm to this test.");