[python] Python webbrowser.open() to open Chrome browser

Here's a somewhat robust way to get the path to Chrome.

(Note that you should do this only if you specifically need Chrome, and not the default browser, or Chromium, or something else.)

def try_find_chrome_path():
    result = None
    if _winreg:
        for subkey in ['ChromeHTML\\shell\\open\\command', 'Applications\\chrome.exe\\shell\\open\\command']:
            try: result = _winreg.QueryValue(_winreg.HKEY_CLASSES_ROOT, subkey)
            except WindowsError: pass
            if result is not None:
                result_split = shlex.split(result, False, True)
                result = result_split[0] if result_split else None
                if os.path.isfile(result):
                    break
                result = None
    else:
        expected = "google-chrome" + (".exe" if os.name == 'nt' else "")
        for parent in os.environ.get('PATH', '').split(os.pathsep):
            path = os.path.join(parent, expected)
            if os.path.isfile(path):
                result = path
                break
    return result