title: $emit from child controller works, but $broadcast from parent scope doesn't
body: <p>When I call <code>$scope.$broadcast</code> none of the events my children are listening to are getting triggered.  A simplified example is below:</p>
  
  <h2>HTML</h2>
  
  <p>Below is a simplified example of what I'm trying to accomplish:</p>
  
  <pre><code>&lt;div ng-app="app" ng-controller="parentCtrl"&gt;
    &lt;div ng-controller="childCtrl"&gt;
      &lt;b&gt;Parent Event:&lt;/b&gt; {{outer}}&lt;br /&gt;
      &lt;b&gt;Child Event:&lt;/b&gt; {{inner}}&lt;br /&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <h2>AngularJs</h2>
  
  <pre><code>mc = angular.module('app', [
    'app.controllers',
  ]);
  
  angular.module('app.controllers', [])
      .controller('parentCtrl', ['$scope', '$http', '$q', function ($scope, $http, $q) {
          $scope.outer = 'not executed';
          $scope.$broadcast('EventFromParent');
          $scope.$on('EventFromChild', function () { 
            $scope.outer = 'executed';
          });        
      }])
      .controller('childCtrl', ['$scope', '$http', function ($scope, $http) {
          $scope.inner = 'not executed';
          $scope.$on('EventFromParent', function () { 
            $scope.inner = 'executed';
          });
          $scope.$emit('EventFromChild');
      }]);
  </code></pre>
  
  <h2>Output</h2>
  
  <p>I expect to see triggered for both Parent and Child, but I don't get triggered for Child.</p>
  
  <pre><code>EXPECTED                      ACTUAL
  ------                        ------
  Parent Event: triggered       Parent Event: triggered
  Child Event: triggered        Child Event: not triggered
  </code></pre>
  
  <h2>Theory</h2>
  
  <p>My guess here is that the child controller is not ready to receive events.  That I need to wait until the DOM is ready, but I don't see how to do that with Angular.  Feel free to tell me that this is just the wrong way to go about what I'm doing too.</p>
  
  <h1><a href="http://plnkr.co/edit/ukM8SzITpOvrvrMg4qYr?p=preview">Plunkr</a></h1>