Add ActivityLog tests for chrome.tabs.executeScript()

chrome/test/data/extensions/activity_log/execute_script_ad_injection/background.js

+// Copyright 2014 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.
+
+// Test that injecting an ad via tabs.executeScript doesn't circumvent
+// detection. This is a very simple test, since the methods are tested much
+// more extensively in the
+// chrome/test/data/extensions/activity_log/ad_injection.
+// If this test grows, it could use the same setup as that test, but there's no
+// need for that at the time.
+
+var didInject = false;
+var code =
+    "document.body.appendChild(document.createElement('iframe')).src = " +
+        "'http://www.known-ads.adnetwork';";
+
+/**
+ * Injects an ad into the tab using chrome.tabs.executeScript().
+ * @param {number} tabId The id of the tab to inject into.
+ */
+function injectScript(tabId) {
+  console.log('injectScript');
+  if (!didInject) {
+    console.log('injecting');
+    didInject = true;
+    chrome.tabs.executeScript(tabId, {code: code}, function() {
+      console.log('injected');
+      chrome.test.sendMessage('Done');
+    });
+  }
+}
+
+// Inject the script when the tab is updated.
+chrome.tabs.onUpdated.addListener(injectScript);