I pressed some button combination and now button text gone for Chrome application

Hi.

I now have no text for Chrome windows buttons, while all other windows' text is there. 

When i unload 7+ Taskbar tweaker, text appears. 

Is it a feature and how to undo it? (i've tried to switch on/off every option in settings and advanced settings with no success)

without 7+ Taskbar tweaker           with 7+ Taskbar tweaker

What I was doing when it happened: 

I was playing a game that make alt shift and control buttons "stuck" in pressed state from time to time.

I switched from the game and started randomly pressing alt/ctrl/shift to make them "unstuck"

I had little success and continued randomly pressing them and probably some other buttons while trying to switch apps with my mouse clicking on taskbar buttons.

Then text disappeared.