Implement chromium.self in content scripts, fix bugs

chrome/test/data/extensions/content_script_inject/script3.js

+// Copyright (c) 2009 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 gotDOMContentLoadedEvent = false;
+
+// Test that at parse time, we have the document element.
+var hasDocumentElement = (document.documentElement.tagName == "HTML");
+
+// TODO(aa): We would like to add more tests here that there are zero child
+// nodes to the documentElement, but unfortunately run_at:document_start is
+// currently buggy and doesn't guarantee that.
+
+window.addEventListener("DOMContentLoaded", function() {
+  gotDOMContentLoadedEvent = true;
+}, false);
+
+// Don't run tests until onload so that we can test that DOMContentLoaded and
+// onload happen after this script runs.  
+window.addEventListener("load", runAllTests, false);
+
+function testRunAtDocumentStart() {
+  assert(hasDocumentElement);
+}
+
+function testGotLoadEvents() {
+  assert(gotDOMContentLoadedEvent);
+}