UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:54.0) Gecko/20100101 Firefox/54.0

Steps to reproduce the problem:
1. Provide a UTC-based date in the official date format and construct it via JavaScript’s Date() function.
2. Convert the UTC-based date to a localDateString and replace the original with it in the DOM
3. Get an incorrect date format

What is the expected behavior?
The date format is expected to be displayed in the following way for the United Kingdom:

- Short: dd/MM/y
- Medium: d MMM y
- Long: d MMMM y
- Full: EEEE, d MMMM y

This means that, as Firefox, Safari and other browsers display correctly, the datestring "2017-05-02T00:00:00+00:00" should be turned into "02/05/2017". Instead, Chrome returns just "2017-5-2".

What went wrong?
The date format is expected to be displayed in the following way for the United Kingdom, according to the system settings of macOS:

- Short: dd/MM/y
- Medium: d MMM y
- Long: d MMMM y
- Full: EEEE, d MMMM y

This means that, as Firefox, Safari and other browsers display correctly, the datestring "2017-05-02T00:00:00+00:00" should be turned into "02/05/2017". Instead, Chrome returns just "2017-5-2", which is not specified anywhere.

Did this work before? No 

Does this work in other browsers? Yes

Chrome version: 58.0.3018.0 (Official Build) canary (64-bit)  Channel: canary
OS Version: OS X 10.12
Flash Version: 

Tested in Chrome stable as well as in Canary.