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

tools/json_schema_compiler/test/tabs.json

 [
   {
     "namespace": "tabs",
     "types": [
       {
         "id": "Tab",
         "type": "object",
         "properties": {
           "id": {"type": "integer", "minimum": 0, "description": "The ID of the tab. Tab IDs are unique within a browser session."},
           "index": {"type": "integer", "minimum": 0, "description": "The zero-based index of the tab within its window."},
@@ skipping 45 matching lines @@
                 "optional": true
               }
             ]
           }
         ]
       },
       {
         "name": "connect",
         "nocompile": true,
         "type": "function",
-        "description": "Connects to the content script(s) in the specified tab. The <a href='extension.html#event-onConnect'>chrome.extension.onConnect</a> 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 <a href='extension.html#event-onConnect'>chrome.runtime.onConnect</a> 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": {
@@ skipping 23 matching lines @@
             "name": "request"
           },
           {
             "type": "function",
             "name": "responseCallback",
             "optional": true,
             "parameters": [
               {
                 "name": "response",
                 "type": "any",
-                "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 <a href='extension.html#property-lastError'>chrome.extension.lastError</a> will be set to the error message."
+                "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 <a href='extension.html#property-lastError'>chrome.runtime.lastError</a> will be set to the error message."
               }
             ]
           }
         ]
       },
       {
         "name": "getSelected",
         "nodoc": true,
         "type": "function",
         "description": "Deprecated. Please use query({'active': true}). Gets the tab that is selected in the specified window.",
@@ skipping 639 matching lines @@
             "name": "removeInfo",
             "properties": {
               "isWindowClosing": {"type": "boolean", "description": "True when the tab is being closed because its window is being closed." }
             }
           }
         ]
       }
     ]
   }
 ]