UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce the problem:
1. Prepare machine with default language different than English (I have used russian and Win10 and Win7 machines)
2. Install Chromium from https://www.chromium.org/getting-involved/download-chromium
3. Open settings page 
4. Open developer tools 
5. You will see in console the following debug message

lazy_load.crisper.js:39 Uncaught (in promise) TypeError: Cannot read property 'displayName' of undefined
    at HTMLElement.getProspectiveUILanguageName_ (lazy_load.crisper.js:39)
    at runMethodEffect (polymer-extracted.js:11)
    at Function._evaluateBinding (polymer-extracted.js:11)
    at Object.runBindingEffect [as fn] (polymer-extracted.js:11)
    at runEffectsForProperty (polymer-extracted.js:11)
    at runEffects (polymer-extracted.js:11)
    at HTMLElement._propagatePropertyChanges (polymer-extracted.js:11)
    at HTMLElement._propertiesChanged (polymer-extracted.js:11)
    at HTMLElement._flushProperties (polymer-extracted.js:11)
    at HTMLElement._flushProperties (polymer-extracted.js:11)
getProspectiveUILanguageName_ @ lazy_load.crisper.js:39

What is the expected behavior?
Clean console

What went wrong?
JS function in the file 
chrome\browser\resources\settings\languages_page\languages_page.js 
looks like this

getProspectiveUILanguageName_: function(prospectiveUILanguage) {    
    return this.languageHelper.getLanguage(prospectiveUILanguage).displayName;
  },

and prospectiveUILanguage variable contains "ru-RU" while function "getLanguage" expect language in 2 symbols format "ru"

Did this work before? N/A 

Chrome version: 73.0.3673.0  Channel: n/a
OS Version: 10.0
Flash Version: