Remove "DifferentialParentRevisionsField" custom field

Summary: Ref T11114. This was obsoleted by UI changes and hacked around for performance in T11404. It no longer does anything.

Test Plan: Grepped for removed class name.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11114

Differential Revision: https://secure.phabricator.com/D17077

src/__phutil_library_map__.php

@@ -473,7 +473,6 @@ phutil_register_library_map(array(
     'DifferentialMailView' => 'applications/differential/mail/DifferentialMailView.php',
     'DifferentialManiphestTasksField' => 'applications/differential/customfield/DifferentialManiphestTasksField.php',
     'DifferentialModernHunk' => 'applications/differential/storage/DifferentialModernHunk.php',
-    'DifferentialParentRevisionsField' => 'applications/differential/customfield/DifferentialParentRevisionsField.php',
     'DifferentialParseCacheGarbageCollector' => 'applications/differential/garbagecollector/DifferentialParseCacheGarbageCollector.php',
     'DifferentialParseCommitMessageConduitAPIMethod' => 'applications/differential/conduit/DifferentialParseCommitMessageConduitAPIMethod.php',
     'DifferentialParseRenderTestCase' => 'applications/differential/__tests__/DifferentialParseRenderTestCase.php',
@@ -5127,7 +5126,6 @@ phutil_register_library_map(array(
     'DifferentialMailView' => 'Phobject',
     'DifferentialManiphestTasksField' => 'DifferentialCoreCustomField',
     'DifferentialModernHunk' => 'DifferentialHunk',
-    'DifferentialParentRevisionsField' => 'DifferentialCustomField',
     'DifferentialParseCacheGarbageCollector' => 'PhabricatorGarbageCollector',
     'DifferentialParseCommitMessageConduitAPIMethod' => 'DifferentialConduitAPIMethod',
     'DifferentialParseRenderTestCase' => 'PhabricatorTestCase',

src/applications/differential/config/PhabricatorDifferentialConfigOptions.php

@@ -36,7 +36,6 @@ final class PhabricatorDifferentialConfigOptions
       new DifferentialProjectsField(),
       new DifferentialViewPolicyField(),
 
-      new DifferentialParentRevisionsField(),
       new DifferentialManiphestTasksField(),
       new DifferentialCommitsField(),
 

src/applications/differential/customfield/DifferentialParentRevisionsField.php

@@ -1,44 +0,0 @@
-<?php
-
-final class DifferentialParentRevisionsField
-  extends DifferentialCustomField {
-
-  public function getFieldKey() {
-    return 'differential:depends-on';
-  }
-
-  public function getFieldName() {
-    return pht('Parent Revisions');
-  }
-
-  public function canDisableField() {
-    return false;
-  }
-
-  public function getFieldDescription() {
-    return pht('Lists revisions this one depends on.');
-  }
-
-  public function getProTips() {
-    return array(
-      pht(
-        'Create a dependency between revisions by writing '.
-        '"%s" in your summary.',
-        'Depends on D123'),
-    );
-  }
-
-  public function shouldAppearInConduitDictionary() {
-    // To improve performance, we exclude this field from Conduit results.
-    // See T11404 for discussion. In modern "differential.revision.search",
-    // this information is available efficiently as an attachment.
-    return false;
-  }
-
-  public function getConduitDictionaryValue() {
-    return PhabricatorEdgeQuery::loadDestinationPHIDs(
-      $this->getObject()->getPHID(),
-      DifferentialRevisionDependsOnRevisionEdgeType::EDGECONST);
-  }
-
-}