Remove unnecessary calls to $apply() since $q guarantees .then are run in digest cycles

This simplifies a lot of code

Author: Hengjie

app/scripts/ng-xdLocalStorage.js

@@ -6,18 +6,8 @@
 
 angular.module('xdLocalStorage', [])
   .service('xdLocalStorage', ['$q', '$rootScope', function ($q, $rootScope) {
-    var iframeReady = false;
     var apiReady = $q.defer();
 
-    var unregister = $rootScope.$watch(function () {
-      return iframeReady;
-    }, function () {
-      if (iframeReady === true) {
-        apiReady.resolve(true);
-        unregister();
-      }
-    });
-
     function waitForApi() {
       if (!xdLocalStorage.wasInit()) {
         throw 'You must init xdLocalStorage in app config before use';
@@ -30,9 +20,7 @@ angular.module('xdLocalStorage', [])
         var defer = $q.defer();
         xdLocalStorage[method].apply(this, args.concat(function () {
           var result = arguments[0];
-          $rootScope.$apply(function () {
-            defer.resolve(result);
-          });
+          defer.resolve(result);
         }));
         return defer.promise;
       });
@@ -41,10 +29,8 @@ angular.module('xdLocalStorage', [])
       init: function (options) {
         var defer = $q.defer();
         options.initCallback = function () {
-          $rootScope.$apply(function () {
-            iframeReady = true;
-            defer.resolve();
-          });
+          apiReady.resolve();
+          defer.resolve();
         };
         xdLocalStorage.init(options);
         return defer.promise;