Make DiffusionQuery extend PhabricatorQuery

Summary: Ref T2683. Provides access to `formatWhereClause()`, etc. I plan to eventually unify the various DiffusionQuery execute methods as well, which all have special names right now (`loadModifiedPaths()`, `loadWhateverBlah()`, etc).

Test Plan: Ran EverythingImplemented test. Browsed Diffusion.

Reviewers: vrana

Reviewed By: vrana

CC: aran

Maniphest Tasks: T2683

Differential Revision: https://secure.phabricator.com/D5251

src/__phutil_library_map__.php

@@ -2224,6 +2224,7 @@ phutil_register_library_map(array(
     'DiffusionPathQueryTestCase' => 'PhabricatorTestCase',
     'DiffusionPathValidateController' => 'DiffusionController',
     'DiffusionPeopleMenuEventListener' => 'PhutilEventListener',
+    'DiffusionQuery' => 'PhabricatorQuery',
     'DiffusionRawDiffQuery' => 'DiffusionQuery',
     'DiffusionRemarkupRule' => 'PhabricatorRemarkupRuleObject',
     'DiffusionRepositoryController' => 'DiffusionController',

src/applications/diffusion/query/DiffusionQuery.php

@@ -1,6 +1,6 @@
 <?php
 
-abstract class DiffusionQuery {
+abstract class DiffusionQuery extends PhabricatorQuery {
 
   private $request;
 
@@ -36,6 +36,10 @@ abstract class DiffusionQuery {
     return $this->request;
   }
 
+  public function execute() {
+    return $this->executeQuery();
+  }
+
   abstract protected function executeQuery();