chromium/third_party/blink/web_tests/external/wpt/html/editing/dnd/platform/file-os-to-os.html

<!doctype html>
<html>
  <head>
    <title>drag and drop - dragging items from the OS to the OS, via the browser window</title>
  </head>
  <body>

    <p>This test is only relevant on platforms where it is possible to switch applications in mid-drag (eg. alt+tab, dragging over taskbar buttons, dragging between restored windows).</p>
    <p>This testcase requires an external application that accepts dragging and dropping of files - eg. your system's file manager. Ensure that two application windows are open for the external application, showing different folders.</p>
    <p>Select a file in the first external application window. Drag the file over the browser window, then over the other external application window and release it. Pass if the file is copied/moved to the second window, as expected by the system.</p>

  </body>
</html>