Do not log the cancelled flipper export as a failure

Summary: Currently cancelling the flipper export logs the event as a failure. This diff introduces one more event log type called cancelled.

Reviewed By: jknoxville

Differential Revision: D16711110

fbshipit-source-id: 308b7e64974610dbb17bd14b2425f6d939c99313

src/utils/errors.tsx

@@ -5,6 +5,12 @@
  * @format
  */
 
+export class CancelledPromiseError extends Error {
+  constructor(msg: string) {
+    super(msg);
+    this.name = 'CancelledPromiseError';
+  }
+}
 export function getStringFromErrorLike(e: any) {
   if (typeof e == 'string') {
     return e;