function matchOpera() {
  if (useUserAgentDataBrand()) {
    // Pre-Chromium Edge doesn't support navigator.userAgentData.
    return false;
  }
  return util.matchUserAgent('Opera');
}
@return {boolean} Whether the user's browser is Opera. Note: Chromium based
    Opera (Opera 15+) is detected as Chrome to avoid unnecessary special
    casing.