Stripping white spaces between an operator and parenthese breaks CSS calc on Chromium

[mkmyuu]

I discovered the following issue with CSS calc and white spaces which breaks your styles in some browsers (e.g. Chrome) while others will work fine (e.g. Firefox):
Pure CSS
width: calc(100% / 3 - (3 - 1) * 1em / 3);
will turn into
width: calc(100% / 3 -(3 - 1) * 1em / 3);
when compressed.

Note the missing white space in front of the opening parenthese. I'd appreciate a fix for that :)