Integrate subscriptions with ApplicationTransactions

Summary: Fixes T2214. For objects which support ApplicationTransaction, use ApplicationTransactions to apply subscription action changes. Principally, this makes clicking "Subscribe" / "Unsubscribe" appear correctly in the transaction log.

Test Plan: Clicked "Subscribe" and "Unsubscribe" a on Macros and Mocks.

Reviewers: chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T2214

Differential Revision: https://secure.phabricator.com/D4986

src/applications/macro/storage/PhabricatorFileImageMacro.php

@@ -1,7 +1,9 @@
 <?php
 
 final class PhabricatorFileImageMacro extends PhabricatorFileDAO
-  implements PhabricatorSubscribableInterface {
+  implements
+    PhabricatorSubscribableInterface,
+    PhabricatorApplicationTransactionInterface {
 
   protected $filePHID;
   protected $phid;
@@ -23,5 +25,13 @@ final class PhabricatorFileImageMacro extends PhabricatorFileDAO
     return false;
   }
 
+  public function getApplicationTransactionEditor() {
+    return new PhabricatorMacroEditor();
+  }
+
+  public function getApplicationTransactionObject() {
+    return new PhabricatorMacroTransaction();
+  }
+
 }