chrome/test/data/extensions/content_capabilities/capability_tests.js

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

(function() {

var getIframe = function() { return document.querySelector('iframe'); };

window.tests = {
  canReadClipboard: function() {
    return document.execCommand('paste');
  },

  canWriteClipboard: function() {
    return document.execCommand('copy');
  },

  canReadClipboardInAboutBlankFrame: function() {
    return getIframe().contentDocument.execCommand('paste');
  },

  canWriteClipboardInAboutBlankFrame: function() {
    return getIframe().contentDocument.execCommand('copy');
  },
};

}());