Added license header

chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js

Index: chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js
diff --git a/chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js b/chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js
index a003719870a753dc3b0cf91b36e979daa13513f6..88ae90cb3222fa1d88da863027aa5721517b7e8f 100644
--- a/chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js
+++ b/chrome/common/extensions/docs/examples/api/tabs/screenshot/screenshot.js
@@ -1,3 +1,7 @@
+// Copyright (c) 2011 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.
+
 // To make sure we can uniquely identify each screenshot tab, add an id as a
 // query param to the url that displays the screenshot.
 var id = 100;
@@ -44,5 +48,9 @@ function takeScreenshot() {
 
 // Listen for a click on the camera icon.  On that click, take a screenshot.
 chrome.browserAction.onClicked.addListener(function(tab) {
-  takeScreenshot();
+  if (tab.url.match(/code.google.com/)) {
+    takeScreenshot();
+  } else {
+    alert('This sample can only take screenshots of code.google.com pages');
+  }
 });