title: Options not getting highlighted
body: <p>I have a multiple select options and select all button. When clicked on select all button then all options should get highlighted. However, in my case when clicked on select all button then I am getting all the options as selected and it's values but the options are not getting highlighted.</p>
  
  <p>Here's my controller code.</p>
  
  <pre><code>$scope.selectedAll = function(){
      $scope.user.profile = []; 
      angular.forEach($scope.userprofiles, function(item){
          $scope.user.profile.push( item.profile);
      }); 
  }
  </code></pre>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div class="label_hd"&gt;Profiles
      &lt;input type="button" 
             id="select_all" 
             ng-click="selectedAll()" 
             name="select_all" 
             value="Select All"&gt;
  &lt;/div&gt;
  &lt;select multiple 
          class="browser-default" 
          name="userprofile" 
          id="userprofile"
          ng-model="user.profile"&gt;
      &lt;option ng-repeat="profile in userprofiles"
              value="{{profile.profile}}"&gt;
              {{ profile.profile_name }}
      &lt;/option&gt;
  &lt;/select&gt;
  </code></pre>