Bug 1037128 - Regression: Contact API usage is being prompt on webpages r=fabrice

dom/contacts/ContactManager.js

@@ -248,10 +248,16 @@ ContactManager.prototype = {
     let permValue =
       Services.perms.testExactPermissionFromPrincipal(principal, type);
     if (permValue == Ci.nsIPermissionManager.ALLOW_ACTION) {
-      aAllowCallback();
+      if (aAllowCallback) {
+        aAllowCallback();
+      }
+      return;
+    } else if (permValue == Ci.nsIPermissionManager.DENY_ACTION ||
+               permValue == Ci.nsIPermissionManager.UNKNOWN_ACTION) {
+      if (aCancelCallback) {
+        aCancelCallback();
+      }
       return;
-    } else if (permValue == Ci.nsIPermissionManager.DENY_ACTION) {
-      aCancelCallback();
     }
 
     // Create an array with a single nsIContentPermissionType element.