[embedlite-components] Add support for MediaManagerVideo permission. …

…JB#53942

In addition to "camera" and "microphone" permissions, the MediaManager
uses one more id "MediaManagerVideo", and does not grant permission to
use camera unless the principal has "MediaManagerVideo" allowed. Add
this permission for one shot each time the camera is requested.

jscomps/EmbedLiteWebrtcUI.js

@@ -118,6 +118,12 @@ WebrtcPermissionRequest.prototype = {
     // If the permission has already been granted
     let result = Services.perms.testExactPermission(this.uri, type);
     if (result == Ci.nsIPermissionManager.ALLOW_ACTION) {
+      if (type == "camera") {
+        // Add one-shot permission to use camera
+        Services.perms.add(this.uri, "MediaManagerVideo",
+                           Ci.nsIPermissionManager.ALLOW_ACTION,
+                           Ci.nsIPermissionManager.EXPIRE_SESSION);
+      }
       // Use first available device. Assume Gecko has them sorted by importance.
       // Perhaps a better algorithm can be implemented here.
       return 0;
@@ -148,6 +154,12 @@ WebrtcPermissionRequest.prototype = {
               && availableDevices
               && availableDevices.length > selectedIndex) {
             this.allowedDevices.appendElement(availableDevices[selectedIndex]);
+            // Add one-shot permission to use camera
+            if (type == "camera") {
+              Services.perms.add(this.uri, "MediaManagerVideo",
+                                 Ci.nsIPermissionManager.ALLOW_ACTION,
+                                 Ci.nsIPermissionManager.EXPIRE_SESSION);
+            }
           }
         }
       }