"Saving changes" and "Saved..." states wrongly appear twice after editing if more than one window is opened

[Softvision-CristinaBadescu]

[Notes]:

• In order to easily observe this issue, resize the windows so you can fully see the "Notes" sidebars.
• No matter how many windows you'll open, the saving changing state appear twice.

[Affected versions]:

• Firefox 57.0.4 and up

[Affected Platforms]:

• All Windows
• All Mac
• All Linux

[Prerequisites]:

• Have a Firefox profile with the latest "Firefox Notes" add-on version (2.2.0dev custom build from 2018-01-18) installed.
• Be logged in a Firefox Notes account.

[Steps to reproduce]:

1. Open Firefox browser with the profile from prerequisites and write something in the sidebar.
2. Open a new window and focus the sidebar.
3. Type again something and observe the changing states from the bottom part of the sidebar.

[Expected result]:

• The "Saving changes" -> "Saved" -> "Synced at.." states appear.

[Actual result]:

• The "Saving changes" -> "Saved" -> "Saving changes" -> "Saved" -> "Synced at.." states appear.

[Additional notes]:

• This issue is also reproducible with Firefox Notes installed from Test Pilot experiment page and with Firefox Notes v2.1.1.rc2.
• Here is a screen recording of the issue:
  

[Natim]

This seems fixed with 2.2.0rc3

[Softvision-CristinaBadescu]

This issue is no longer reproducible using Firefox Notes v2.2.0rc5, or Firefox Notes v2.2.0dev (custom build 2018-02-05), on latest Nightly build 60.0a1 (2018-02-04), on Windows 10 x64, Mac 10.12.6 and Arch Linux 4.12.

However, you can briefly observe the transition from "Saved" -> "Synced..", but only for such a short moment, that I cannot even catch on screenrecording.