Slightly modernize all Diffusion edit endpoints

Summary: Ref T4245. Prepares edit endpoints for more flexible repository identifiers.

Test Plan:
  - Added, edited, deleted mirror.
  - Created repository.
  - Edited basic repository information.
  - Edited policies for a repository.
  - Activated/deactivated repository.
  - Updated a repository.
  - Hit "Delete" dialog for a repository.
  - Edited hosting.
  - Toggled dangerous changes.
  - Edited branches.
  - Edited automation.
  - Tested automation.
  - Edited storage.
  - Edited staging.
  - Edited encoding.
  - Edited symbols.
  - Edited branches.
  - Edited actions.
  - Tried to do edits as an unprivileged user.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T4245

Differential Revision: https://secure.phabricator.com/D14945

src/applications/diffusion/controller/DiffusionRepositoryTestAutomationController.php

@@ -4,7 +4,7 @@ final class DiffusionRepositoryTestAutomationController
   extends DiffusionRepositoryEditController {
 
   public function handleRequest(AphrontRequest $request) {
-    $response = $this->loadDiffusionContext();
+    $response = $this->loadDiffusionContextForEdit();
     if ($response) {
       return $response;
     }
@@ -13,19 +13,6 @@ final class DiffusionRepositoryTestAutomationController
     $drequest = $this->getDiffusionRequest();
     $repository = $drequest->getRepository();
 
-    $repository = id(new PhabricatorRepositoryQuery())
-      ->setViewer($viewer)
-      ->requireCapabilities(
-        array(
-          PhabricatorPolicyCapability::CAN_VIEW,
-          PhabricatorPolicyCapability::CAN_EDIT,
-        ))
-      ->withIDs(array($repository->getID()))
-      ->executeOne();
-    if (!$repository) {
-      return new Aphront404Response();
-    }
-
     $edit_uri = $this->getRepositoryControllerURI($repository, 'edit/');
 
     if (!$repository->canPerformAutomation()) {