Allow comments in extension config files.

chrome/common/extensions/api/experimental.input.virtualKeyboard.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.input.virtualKeyboard",
     "nodoc": true,
     "types": [],
     "functions": [
       {
         "name": "sendKeyboardEvent",
         "type": "function",
         "description": "Sends a keyboard event to Chrome.",
@@ skipping 115 matching lines @@
             "type": "string",
             "name": "type",
             "enum": ["none", "text", "password", "search", "email", "number", "tel", "url"],
             "description": "Type of the current focused input field."
           }
         ]
       }
     ]
   }
 ]