Updating JSON Schema Compiler to add description field to schemas.

chrome/common/extensions/api/experimental_history.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "experimental.history",
+    "description": "Use the <code>chrome.experimental.history</code> API to interact with the browser's record of most visited pages.",
     "types": [
       {
         "id": "MostVisitedItem",
         "type": "object",
         "properties": {
            "url": {"type": "string", "description": "The URL navigated to by a user."},
            "title": {"type": "string", "description": "The title of the page when it was last loaded."}
         }
       }
     ],
@@ skipping 17 matching lines @@
             "type": "function",
             "parameters": [
               { "name": "results", "type": "array", "items":  { "$ref": "MostVisitedItem"} }
             ]
           }
         ]
       }
     ]
   }
 ]