Simplify Differential field selector

Summary:
If I use my own selector then it doesn't respect Phabricator config.

Also I hated this method.

Test Plan: Used default selector, displayed revision.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D3307

src/applications/differential/field/selector/DifferentialDefaultFieldSelector.php

@@ -23,15 +23,7 @@ final class DifferentialDefaultFieldSelector
     $fields = array(
       new DifferentialTitleFieldSpecification(),
       new DifferentialSummaryFieldSpecification(),
-    );
+      new DifferentialTestPlanFieldSpecification(),
-
-    if (PhabricatorEnv::getEnvConfig('differential.show-test-plan-field')) {
-      $fields[] = new DifferentialTestPlanFieldSpecification();
-    }
-
-    $fields = array_merge(
-      $fields,
-      array(
       new DifferentialRevisionStatusFieldSpecification(),
       new DifferentialAuthorFieldSpecification(),
       new DifferentialReviewersFieldSpecification(),
@@ -42,16 +34,8 @@ final class DifferentialDefaultFieldSelector
       new DifferentialCommitsFieldSpecification(),
       new DifferentialDependenciesFieldSpecification(),
       new DifferentialManiphestTasksFieldSpecification(),
-      ));
+      new DifferentialHostFieldSpecification(),
-
+      new DifferentialPathFieldSpecification(),
-    if (PhabricatorEnv::getEnvConfig('differential.show-host-field')) {
-      $fields[] = new DifferentialHostFieldSpecification();
-      $fields[] = new DifferentialPathFieldSpecification();
-    }
-
-    $fields = array_merge(
-      $fields,
-      array(
       new DifferentialBranchFieldSpecification(),
       new DifferentialArcanistProjectFieldSpecification(),
       new DifferentialApplyPatchFieldSpecification(),
@@ -60,7 +44,7 @@ final class DifferentialDefaultFieldSelector
       new DifferentialDateModifiedFieldSpecification(),
       new DifferentialDateCreatedFieldSpecification(),
       new DifferentialAuditorsFieldSpecification(),
-      ));
+    );
 
     return $fields;
   }

src/applications/differential/field/specification/DifferentialHostFieldSpecification.php

@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,7 @@ final class DifferentialHostFieldSpecification
   extends DifferentialFieldSpecification {
 
   public function shouldAppearOnRevisionView() {
-    return true;
+    return PhabricatorEnv::getEnvConfig('differential.show-host-field');
   }
 
   public function renderLabelForRevisionView() {

src/applications/differential/field/specification/DifferentialPathFieldSpecification.php

@@ -20,7 +20,7 @@ final class DifferentialPathFieldSpecification
   extends DifferentialFieldSpecification {
 
   public function shouldAppearOnRevisionView() {
-    return true;
+    return PhabricatorEnv::getEnvConfig('differential.show-host-field');
   }
 
   public function renderLabelForRevisionView() {

src/applications/differential/field/specification/DifferentialTestPlanFieldSpecification.php

@@ -25,7 +25,7 @@ final class DifferentialTestPlanFieldSpecification
   private $error = false;
 
   public function shouldAppearOnEdit() {
-    return true;
+    return PhabricatorEnv::getEnvConfig('differential.show-test-plan-field');
   }
 
   protected function didSetRevision() {
@@ -69,7 +69,7 @@ final class DifferentialTestPlanFieldSpecification
   }
 
   public function shouldAppearOnCommitMessage() {
-    return true;
+    return PhabricatorEnv::getEnvConfig('differential.show-test-plan-field');
   }
 
   public function getCommitMessageKey() {