Hi, long time user, first time issuer.

I think I found a bug with the Profiler component. When I click on the `Save profile...` button at the top nothing happens and there appears to be no new files in my Downloads folder. I think it might be silently failing and that's why I am not getting any response.  Has anyone else ran into this issue?

Another thing I would like to mention is that I haven't looked through all of the documentation material about the new Profiler. I only read [this introductory blog post](https://reactjs.org/blog/2018/09/10/introducing-the-react-profiler.html), so if this issue is addressed elsewhere I apologize and also request the source to that solution.

Thank you for your time!

**Versions:**
 * `React DevTools 4.0.5`
 * `Firefox: 68.0.2(64-bit)`
 * `Ubuntu: 18.04`

}
    },
    [modalDialogDispatch, profilerStore],
  );
  return (
    <Fragment>
      <div className={styles.VRule} />
      <input
        ref={inputRef}
        className={styles.Input}
        type="file"
        onChange={handleFiles}
        tabIndex={-1}
      />
      <Button
        disabled={isProfiling}
        onClick={uploadData}
        title="Load profile...">
        <ButtonIcon type="import" />
      </Button>
      <Button
        disabled={isProfiling || !profilerStore.didRecordCommits}
        onClick={downloadData}
        title="Save profile...">
        <ButtonIcon type="export" />
      </Button>
    </Fragment>
  );
}