Add a "Subtype" tag to the task graph view in Maniphest

Summary: See PHI1466. When an install defines task subtypes, show them on the task graph.

Test Plan:
  - On desktop with subtypes defined, column is visible.
  - On desktop with subtypes not defined, column is hidden.
  - On mobile, column is hidden.

{F6896845}

Differential Revision: https://secure.phabricator.com/D20842

src/infrastructure/graph/ManiphestTaskGraph.php

@@ -84,9 +84,18 @@ final class ManiphestTaskGraph
         ' ',
         $link,
       );
+
+      $subtype_tag = null;
+
+      $subtype = $object->newSubtypeObject();
+      if ($subtype && $subtype->hasTagView()) {
+        $subtype_tag = $subtype->newTagView()
+          ->setSlimShady(true);
+      }
     } else {
       $status = null;
       $assigned = null;
+      $subtype_tag = null;
       $link = $viewer->renderHandle($phid);
     }
 
@@ -115,18 +124,23 @@ final class ManiphestTaskGraph
       $marker,
       $trace,
       $status,
+      $subtype_tag,
       $assigned,
       $link,
     );
   }
 
   protected function newTable(AphrontTableView $table) {
+    $subtype_map = id(new ManiphestTask())->newEditEngineSubtypeMap();
+    $has_subtypes = ($subtype_map->getCount() > 1);
+
     return $table
       ->setHeaders(
         array(
           null,
           null,
           pht('Status'),
+          pht('Subtype'),
           pht('Assigned'),
           pht('Task'),
         ))
@@ -136,12 +150,15 @@ final class ManiphestTaskGraph
           'threads',
           'graph-status',
           null,
+          null,
           'wide pri object-link',
         ))
       ->setColumnVisibility(
         array(
           true,
           !$this->getRenderOnlyAdjacentNodes(),
+          true,
+          $has_subtypes,
         ))
       ->setDeviceVisibility(
         array(
@@ -150,6 +167,11 @@ final class ManiphestTaskGraph
           // On mobile, we only show the actual graph drawing if we're on the
           // standalone page, since it can take over the screen otherwise.
           $this->getIsStandalone(),
+          true,
+
+          // On mobile, don't show subtypes since they're relatively less
+          // important and we're more pressured for space.
+          false,
         ));
   }
 
@@ -180,6 +202,7 @@ final class ManiphestTaskGraph
       null,
       null,
       null,
+      null,
       pht("\xC2\xB7 \xC2\xB7 \xC2\xB7"),
     );
   }