Provide getObjectOwnerPHID() on inline comment views

Summary:
This returns the PHID of the current revision owner, or the commit author, if one exists.

NOTE: For drafts, we currently return `null`; I'll fix that in a future change. Should be correct for submitted comments.

Test Plan: Added an inline, nothing seemed broken.

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Differential Revision: https://secure.phabricator.com/D12185

src/applications/diffusion/controller/DiffusionDiffController.php

@@ -95,6 +95,7 @@ final class DiffusionDiffController extends DiffusionController {
     $parser->setCanMarkDone(
       ($commit->getAuthorPHID()) &&
       ($viewer->getPHID() == $commit->getAuthorPHID()));
+    $parser->setObjectOwnerPHID($commit->getAuthorPHID());
 
     $parser->setWhitespaceMode(
       DifferentialChangesetParser::WHITESPACE_SHOW_ALL);