Lazily load extension API schemas

chrome/common/extensions/api/session_restore.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": "sessionRestore",
-    "dependencies": [ "tabs", "windows" ],
     "types": [
       {
         "id": "ClosedEntry",
         "type": "object",
         "properties": {
           "id": {"type": "integer", "minimum": 0, "description": "The ID of the browser session."},
           "timestamp": {"type": "integer", "description": "The time when the window or tab was closed, represented in milliseconds since the epoch"},
           "tab": {"$ref": "tabs.Tab", "optional": true, "description": "The closed $ref:tabs.Tab, if this entry describes a tab. Either this or $ref:ClosedEntry.window will be set."},
           "window": {"$ref": "windows.Window", "optional": true, "description": "The closed $ref:windows.Window, if this entry describes a window. Either this or $ref:ClosedEntry.tab will be set."}
         }
@@ skipping 41 matching lines @@
         "type": "function",
         "description": "Reopens a $ref:ClosedEntry, with an optional callback to run when the entry has been restored.",
         "parameters": [
           {"type": "integer", "name": "id", "optional": true, "description": "The id of the $ref:ClosedEntry to restore."},
           {"type": "function", "name": "callback", "optional": true, "parameters": []}
         ]
       }
     ]
   }
 ]