This test checks that fr tracks are properly sized whenever grid have intrinsic sizes.

XXX XXX
PASS
XXX XXX
FAIL:
Expected 30 for width, but got 70. 

<div class="container">
  <div class="grid minContent" data-expected-width="30" data-expected-height="10">
    <div>XXX XXX</div>
  </div>
</div>
XXX XXX
PASS
XXX XXX
PASS
XXX XXX
PASS
