Trim WebHookPostSerializer further.

app/serializers/post_serializer.rb

@@ -374,6 +374,10 @@ class PostSerializer < BasicPostSerializer
     object.revisions.size > 0
   end
 
+  def include_hidden_reason_id?
+    object.hidden
+  end
+
   private
 
     def topic

app/serializers/web_hook_post_serializer.rb

@@ -12,6 +12,12 @@ class WebHookPostSerializer < PostSerializer
     can_delete
     can_recover
     can_wiki
+    actions_summary
+    can_view_edit_history
+    yours
+    primary_group_flair_url
+    primary_group_flair_bg_color
+    primary_group_flair_color
   }.each do |attr|
     define_method("include_#{attr}?") do
       false