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chromium/third_party/blink/web_tests/editing/pasteboard/copy-cut-paste-supported.html 

<!doctype html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
test(function() {
  assert_true(document.queryCommandSupported('copy'));
  assert_true(document.queryCommandSupported('cut'));
  assert_true(document.queryCommandSupported('paste'));

  assert_true(window.testRunner !== undefined, 'This test requires testRunner');
  testRunner.setJavaScriptCanAccessClipboard(false);

  assert_false(document.queryCommandSupported('paste'));
});
</script>