Use shrink-to-fit for width for Button, input, select, textarea, and legend treat width value of 'auto' as 'intrinsic'.
Per CSS 2.1 section 10.3.8, the width should be the width an input would normally have (rule 1 in 10.3.8), and the 'right' value should be ignored because the values are over-constrained (rule 6 in 10.3.8).
BUG=
281380
Committed:
https://src.chromium.org/viewvc/blink?view=rev&revision=159860