function didUpdateSinceLastCheck() {
    var chromeVersion = /Chrome\/(\d+)\./.exec(navigator.userAgent);
    chromeVersion = chromeVersion && chromeVersion[1];
    if (!chromeVersion || localStorage.telemetryLastVersion === chromeVersion) {
      return false;
    }
    updateLocalStorage("telemetryLastVersion", chromeVersion);
    return true;
  }
Returns whether the browser has received a major update since the last call
to this function.