Extend the ViewAjaxController tests.

1: vdc-2120589-1.patch queued for re-testing.

more test++

Some minor issues other then that it is RTBC.

1. +++ b/core/modules/views/tests/Drupal/views/Tests/Controller/ViewAjaxControllerTest.php
   @@ -133,10 +133,88 @@ public function testAjaxView() {
   +    $display_handler = $this->getMockBuilder('Drupal\views\Plugin\views\display\DisplayPluginBase')
   ...
   +    $display_bag = $this->getMockBuilder('\Drupal\views\DisplayBag')
   ...
   +    $display_handler = $this->getMockBuilder('Drupal\views\Plugin\views\display\DisplayPluginBase')
   ...
   +    $display_bag = $this->getMockBuilder('\Drupal\views\DisplayBag')
   

   I think standard is not to use \ at start.

2. +++ b/core/modules/views/tests/Drupal/views/Tests/Controller/ViewAjaxControllerTest.php
   @@ -170,6 +248,32 @@ protected function setupValidMocks() {
   +  protected function getCommands(ViewAjaxResponse $response) {
   

   function missing description line.

3. +++ b/core/modules/views/tests/Drupal/views/Tests/Controller/ViewAjaxControllerTest.php
   @@ -170,6 +248,32 @@ protected function setupValidMocks() {
   +   * Ensure that the main view content command is added.
   

   Ensures

Thanks for the fixes @dawehner. RTBC +1.

Yay moar tests!

Committed and pushed to 8.x. Thanks!