Bug 861905 - Contacts API: Shortcut permission check in the child. r=mounir

dom/contacts/ContactManager.js

@@ -20,6 +20,10 @@ XPCOMUtils.defineLazyGetter(Services, "DOMRequest", function() {
   return Cc["@mozilla.org/dom/dom-request-service;1"].getService(Ci.nsIDOMRequestService);
 });
 
+XPCOMUtils.defineLazyServiceGetter(this, "pm",
+                                   "@mozilla.org/permissionmanager;1",
+                                   "nsIPermissionManager");
+
 XPCOMUtils.defineLazyServiceGetter(this, "cpmm",
                                    "@mozilla.org/childprocessmessagemanager;1",
                                    "nsIMessageSender");
@@ -559,6 +563,15 @@ ContactManager.prototype = {
         access = "unknown";
       }
 
+    // Shortcut for ALLOW_ACTION so we avoid a parent roundtrip
+    let type = "contacts-" + access;
+    let permValue =
+      pm.testExactPermissionFromPrincipal(this._window.document.nodePrincipal, type);
+    if (permValue == Ci.nsIPermissionManager.ALLOW_ACTION) {
+      aAllowCallback();
+      return;
+    }
+
     let requestID = this.getRequestId({
       request: aRequest,
       allow: function() {