Check for warnings when loading extensions in browser tests.

chrome/test/data/extensions/api_test/webnavigation/test_getFrame.js

-<script>
+// 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.
+
 var URL = chrome.extension.getURL("getFrame/a.html");
 var tabId = -1;
 var processId = -1;
 
 chrome.test.runTests([
   function testGetFrame() {
     chrome.tabs.create({"url": "about:blank"}, function(tab) {
       tabId = tab.id;
       var done = chrome.test.listenForever(
         chrome.webNavigation.onCommitted,
@@ skipping 31 matching lines @@
         chrome.test.assertEq(
             [{errorOccurred: false,
               frameId: 0,
               processId: processId,
               url: URL}],
              details);
         chrome.test.succeed();
     });
   }
 ]);
-</script>