message: Set window.windowError if there is an unhandled js exception or promise rejection.
diff: @@ -180,6 +180,8 @@ store.dispatch(getCRDs);
  analyticsSvc.push({tier: 'tectonic'});
  +window.windowError = false;
  +
  window.onerror = function (message, source, lineno, colno, optError={}) {
  try {
  const e = `${message} ${source} ${lineno} ${colno}`;
  @@ -192,6 +194,7 @@ window.onerror = function (message, source, lineno, colno, optError={}) {
  // ignore
  }
  }
  + window.windowError = true;
  };
  window.onunhandledrejection = function (e) {
  @@ -205,6 +208,7 @@ window.onunhandledrejection = function (e) {
  // ignore
  }
  }
  + window.windowError = true;
  };
  render((
  