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

chrome/test/data/extensions/api_test/filesystem_handler_lazy_background/background.js

 // 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.
 
 /*
 This extension is a file intent handler with transient background page and does
 the following during the test:
 
 1. It first registers content hander.
 2. When content handler callback is invoked, opens tab.html page and passes
@@ skipping 25 matching lines @@
         break;
       default:
         msg = 'Unknown Error';
         break;
     };
   }
 
   // The ID of the extension we want to talk to.
   var fileBrowserExtensionId = "ddammdhioacbehjngdmkjcjbnfginlla";
 
-  chrome.extension.sendMessage(fileBrowserExtensionId,
+  chrome.runtime.sendMessage(fileBrowserExtensionId,
                                {fileContent: null,
                                 error: {message: "File handler error: " + msg}},
                                function(response) {});
 };
 
 function runFileSystemHandlerTest(entries) {
   if (!entries || entries.length != 1 || !entries[0]) {
     errorCallback({message: "Invalid file entries"});
     return;
   }
@@ skipping 13 matching lines @@
     return;
   }
   chrome.tabs.get(details.tab_id, function(tab) {
     if (tab.title != "file browser component test") {
       errorCallback({message: "Unexpected tab title: " + tab.title});
       return;
     }
     runFileSystemHandlerTest(file_entries);
   });
 });