Update references to the extension messaging APIs to point to the "runtime"

chrome/common/extensions/api/context_menus.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": "contextMenus",
     "dependencies": [ "tabs" ],
     "types": [
       {
@@ skipping 60 matching lines @@
             "optional": true,
             "description": "A flag indicating the state of a checkbox or radio item after it is clicked."
           }
         }
       }
     ],
     "functions": [
       {
         "name": "create",
         "type": "function",
-        "description": "Creates a new context menu item. Note that if an error occurs during creation, you may not find out until the creation callback fires (the details will be in chrome.extension.lastError).",
+        "description": "Creates a new context menu item. Note that if an error occurs during creation, you may not find out until the creation callback fires (the details will be in chrome.runtime.lastError).",
         "returns": {
           "choices": [
             { "type": "integer" },
             { "type": "string" }
           ],
           "description": "The ID of the newly created item."
         },
         "parameters": [
           {
             "type": "object",
@@ skipping 71 matching lines @@
                 "type": "boolean",
                 "optional": true,
                 "description": "Whether this context menu item is enabled or disabled. Defaults to true."
               }
             }
           },
           {
             "type": "function",
             "name": "callback",
             "optional": true,
-            "description": "Called when the item has been created in the browser. If there were any problems creating the item, details will be available in chrome.extension.lastError.",
+            "description": "Called when the item has been created in the browser. If there were any problems creating the item, details will be available in chrome.runtime.lastError.",
             "parameters": []
           }
         ]
       },
       {
         "name": "update",
         "type": "function",
         "description": "Updates a previously created context menu item.",
         "parameters": [
           {
@@ skipping 120 matching lines @@
             "name": "tab",
             "$ref": "tabs.Tab",
             "description": "The details of the tab where the click took place. If the click did not take place in a tab, this parameter will be missing.",
             "optional": true
           }
         ]
       }
     ]
   }
 ]