more bookmark tests, plus fix a couple of API bugs

chrome/common/extensions/api/extension_api.json

 [
   {
     "namespace": "extension",
     "types": [
       {
         "id": "Port",
         "type": "object",
         "description": "An object which allows two way communication with other pages.",
         "properties": {
           "name": {"type": "string"},
@@ skipping 813 matching lines @@
         "parameters": [
           {"type": "string", "name": "id"},
           {
             "type": "object",
             "name": "destination",
             "properties": {
               "parentId": {"type": "string"},
               "index": {"type": "integer", "minimum": 0, "optional": true}
             }
           },
-          {"type": "function", "name": "callback", "optional": true, "parameters": []}
+          {
+            "type": "function",
+            "name": "callback",
+            "optional": true,
+            "parameters": [
+              {"name": "result", "$ref": "BookmarkTreeNode" }
+            ]
+          }
         ]
       },
       {
         "name": "update",
         "type": "function",
         "description": "",
         "parameters": [
           {"type": "string", "name": "id"},
           {
             "type": "object",
@@ skipping 197 matching lines @@
         "type": "function",
         "description": "Logs a message during internal unit testing.",
         "parameters": [
           {"type": "string", "name": "message"}
         ]
       }
     ],
     "events": []
   }
 ]