Sync web-platform-tests PR 29004 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/29004
Details from upstream follow.

b'Ian Kilpatrick <ikilpatrick@chromium.org>' wrote:

[GridNG] Fix various grid caching bugs.

This patch adjusts layouts caching logic for grid.
There are a few classes of fixes:

1. Clearing |intrinsic_block_size| when we previously had an "extrinsic"
   constraint (fixed, or stretching size).

   Here we can't trust the |intrinsic_block_size| as it is dependent
   on the extrinsic constraint.
   This also caught a bug in flexbox that it was possible to use a bad
   intrinsic block-size when stretching in the block-axis.

2. Clearing |intrinsic_block_size| when we have %-based block-sizes.

   Here there are cases (with min-width/max-width) where a repeater
   might be different causing an incorrect block-size.
   See: dynamic-grid-with-auto-fill.html

3. Miss the cache if our initial block-size changes. This is different
   to other layout modes, but basically due to 'auto' tracks stretching
   to the available block-size, we need this check.
   This is super common within a column flexbox.

Bug: 1045599
Change-Id: Ic9a16b598a4957bea7fc2bf2550fbf3335b84aff

Reviewed-on: https://chromium-review.googlesource.com/2898150
WPT-Export-Revision: e4c20c86575a136667f2af37211590973b531b6e

https://hg.mozilla.org/mozilla-central/rev/bcd7fcc0dd5f