Consider merging https://chromium.googlesource.com/chromium/blink/+/8dc2b41346856d256b98a64fabfc4fbb9db1a5a6 The RenderGrid support for calc() was already there but we had to add also the CSSComputedStyle support. According to the specs, http://dev.w3.org/csswg/css-grid/#resolved-track-list, we must show the used value. This change also brings several new tests.
Already merged in another bug *** This bug has been marked as a duplicate of bug 103761 ***