Clean up ancestor path implementation.

* mpull for cleaner ancestor access
* move implementation to PhabricatorProject
  * as new function getDisplayNameWithAncestorPath
  * no pht usage, since there are no localisable items

src/applications/project/storage/PhabricatorProject.php

@@ -585,6 +585,18 @@ final class PhabricatorProject extends PhabricatorProjectDAO
     return $name;
   }
 
+  public function getDisplayNameWithAncestorPath() {
+      // Figure out the ancestors for this project
+      // so that we can prepend that to the display name.
+      $ancestors = mpull(array_reverse($this->getAncestorProjects()), 'getName');
+      $ancestors[] = $this->getName();
+
+      $project_name_with_path = implode(' > ', $ancestors);
+
+      // no pht usage, since we don't have translatable items.
+      return $project_name_with_path;
+  }
+
   public function getDisplayIconKey() {
     if ($this->isMilestone()) {
       $key = PhabricatorProjectIconSet::getMilestoneIconKey();

src/applications/project/typeahead/PhabricatorProjectDatasource.php

@@ -105,18 +105,6 @@ final class PhabricatorProjectDatasource
 
       $all_strings = array();
 
-      // Figure out the ancestors for this project
-      // so that we can prepend that to the display name.
-      $ancestors = array_reverse($proj->getAncestorProjects());
-      $ancestor_strings = array();
-      foreach ($ancestors as $ancestor) {
-        $ancestor_strings[] = $ancestor->getName();
-      }
-      $ancestor_strings = implode(' > ', $ancestor_strings);
-      if (strlen($ancestor_strings) > 0) {
-        $ancestor_strings = $ancestor_strings.' > ';
-      }
-
       // NOTE: We list the project's name first because results will be
       // sorted into prefix vs content phases incorrectly if we don't: it
       // will look like "Parent (Milestone)" matched "Parent" as a prefix,
@@ -135,7 +123,7 @@ final class PhabricatorProjectDatasource
 
       $proj_result = id(new PhabricatorTypeaheadResult())
         ->setName($all_strings)
-        ->setDisplayName($ancestor_strings.$proj->getDisplayName())
+        ->setDisplayName($proj->getDisplayNameWithAncestorPath())
         ->setDisplayType($proj->getDisplayIconName())
         ->setURI($proj->getURI())
         ->setPHID($phid)