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

chrome/common/extensions/api/tabs.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": "tabs",
     "dependencies": [ "extension", "windows" ],
     "types": [
       {
@@ skipping 67 matching lines @@
                 "optional": true
               }
             ]
           }
         ]
       },
       {
         "name": "connect",
         "nocompile": true,
         "type": "function",
-        "description": "Connects to the content script(s) in the specified tab. The $ref:extension.onConnect event is fired in each content script running in the specified tab for the current extension. For more details, see <a href='content_scripts.html#messaging'>Content Script Messaging</a>.",
+        "description": "Connects to the content script(s) in the specified tab. The $ref:runtime.onConnect event is fired in each content script running in the specified tab for the current extension. For more details, see <a href='content_scripts.html#messaging'>Content Script Messaging</a>.",
         "parameters": [
           {
             "type": "integer",
             "name": "tabId",
             "minimum": 0
           },
           {
             "type": "object",
             "name": "connectInfo",
             "properties": {
               "name": { "type": "string", "optional": true, "description": "Will be passed into onConnect for content scripts that are listening for the connection event." }
             },
             "optional": true
           }
         ],
         "returns": {
-          "$ref": "extension.Port",
-          "description": "A port that can be used to communicate with the content scripts running in the specified tab. The port's $ref:extension.Port event is fired if the tab closes or does not exist. "
+          "$ref": "runtime.Port",
+          "description": "A port that can be used to communicate with the content scripts running in the specified tab. The port's $ref:runtime.Port event is fired if the tab closes or does not exist. "
         }
       },
       {
         "name": "sendRequest",
         "nodoc": true,
         "nocompile": true,
         "type": "function",
         "description": "Deprecated: Please use sendMessage.",
         "parameters": [
           {
@@ skipping 16 matching lines @@
                 "description": "The JSON response object sent by the handler of the request. If an error occurs while connecting to the specified tab, the callback will be called with no arguments and $ref:runtime.lastError will be set to the error message."
               }
             ]
           }
         ]
       },
       {
         "name": "sendMessage",
         "nocompile": true,
         "type": "function",
-        "description": "Sends a single message to the content script(s) in the specified tab, with an optional callback to run when a response is sent back.  The $ref:extension.onMessage event is fired in each content script running in the specified tab for the current extension.",
+        "description": "Sends a single message to the content script(s) in the specified tab, with an optional callback to run when a response is sent back.  The $ref:runtime.onMessage event is fired in each content script running in the specified tab for the current extension.",
         "parameters": [
           {
             "type": "integer",
             "name": "tabId",
             "minimum": 0
           },
           {
             "type": "any",
             "name": "message"
           },
@@ skipping 761 matching lines @@
             "properties": {
               "windowId": {"type": "integer", "minimum": 0, "description": "the window whose tab is closed." },
               "isWindowClosing": {"type": "boolean", "description": "True when the tab is being closed because its window is being closed." }
             }
           }
         ]
       }
     ]
   }
 ]