Minor, formalize changeset response class.

src/applications/differential/controller/changesetview/DifferentialChangesetViewController.php

@@ -211,14 +211,13 @@ final class DifferentialChangesetViewController extends DifferentialController {
     $mcov = $parser->renderModifiedCoverage();
 
     if ($request->isAjax()) {
-      $content = array(
-        'coverage'  => array(
-          'differential-mcoverage-'.md5($changeset->getFilename()) => $mcov,
-        ),
-        'changeset' => $output,
+      $coverage = array(
+        'differential-mcoverage-'.md5($changeset->getFilename()) => $mcov,
       );
-      return id(new AphrontAjaxResponse())
-        ->setContent($content);
+
+      return id(new PhabricatorChangesetResponse())
+        ->setRenderedChangeset($output)
+        ->setCoverage($coverage);
     }
 
     Javelin::initBehavior('differential-show-more', array(

src/applications/differential/controller/changesetview/__init__.php

@@ -10,7 +10,6 @@ phutil_require_module('arcanist', 'unit/result');
 
 phutil_require_module('phabricator', 'aphront/response/400');
 phutil_require_module('phabricator', 'aphront/response/404');
-phutil_require_module('phabricator', 'aphront/response/ajax');
 phutil_require_module('phabricator', 'aphront/response/redirect');
 phutil_require_module('phabricator', 'aphront/writeguard');
 phutil_require_module('phabricator', 'applications/differential/controller/base');
@@ -24,6 +23,7 @@ phutil_require_module('phabricator', 'applications/files/storage/file');
 phutil_require_module('phabricator', 'applications/markup/engine');
 phutil_require_module('phabricator', 'applications/phid/handle/data');
 phutil_require_module('phabricator', 'infrastructure/diff/engine');
+phutil_require_module('phabricator', 'infrastructure/diff/response');
 phutil_require_module('phabricator', 'infrastructure/javelin/api');
 
 phutil_require_module('phutil', 'utils');