Create a mechanism define declarative rules via the extension manifest.

extensions/common/api/events.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": "events",
     "description": "The <code>chrome.events</code> namespace contains common types used by APIs dispatching events to notify you when something interesting happens.",
     "compiler_options": {
       "implemented_in": "extensions/browser/api/declarative/declarative_api.h"
     },
     "types": [
       {
         "id": "Rule",
         "type": "object",
         "description": "Description of a declarative rule for handling events.",
         "properties": {
           "id": {
             "type": "string",
             "optional": true,
             "description": "Optional identifier that allows referencing this rule."
           },
+          "removable": {

[not at google - send to devlin, 2015/06/04 17:58:49]

This shouldn't be part of the public API, instead, annotate it in the internal
data structure you use.

[danduong, 2015/06/04 19:10:59]

Which internal data-structure. Part of the reason why it is here is because how
the serialization to storage works. 

[not at google - send to devlin, 2015/06/04 19:23:53]

However rules are implemented in C++. you're changing the public API here.

[danduong, 2015/06/04 21:39:40]

Done.

+            "type": "boolean",
+            "optional": true,
+            "description":  "False if the rule is not programmatically removable."
+          },
           "tags": {
             "type": "array",
             "items": {"type": "string"},
             "optional": true,
             "description":  "Tags can be used to annotate rules and perform operations on sets of rules."
           },
           "conditions": {
             "type": "array",
             "items": {"type": "any"},
             "description": "List of conditions that can trigger the actions."
@@ skipping 293 matching lines @@
                 {"type": "array", "items": {"type": "integer"}, "description": "A pair of integers identiying the start and end (both inclusive) of a port range."}
               ]
             }
           }
         }
       }
     ]
   }
 ]