Added check to prevent extensions from injecting scrips into other extensions

chrome/test/data/extensions/api_test/content_scripts/other_extensions/iframe_content.js

Index: chrome/test/data/extensions/api_test/content_scripts/other_extensions/iframe_content.js
diff --git a/chrome/test/data/extensions/api_test/content_scripts/other_extensions/iframe_content.js b/chrome/test/data/extensions/api_test/content_scripts/other_extensions/iframe_content.js
new file mode 100644
index 0000000000000000000000000000000000000000..0e794a0318ce4a7b62fe237c4c82c8edf785f448
--- /dev/null
+++ b/chrome/test/data/extensions/api_test/content_scripts/other_extensions/iframe_content.js
@@ -0,0 +1,15 @@
+// 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.
+
+document.addEventListener('DOMContentLoaded', function() {
+  var id = window.setInterval(function() {
+    clearInterval(id);
+    var parent_extension_page = unescape(location.hash.replace('#', ''));
+
+    console.log('PAGE: Sending content to parent extension page - ' +
+                parent_extension_page);
+    window.parent.postMessage(document.getElementById('content').innerText,
+                              parent_extension_page);
+  }, 10);
+});