[css-logical] Fix computed style of logical size properties

Unlike 'width' and 'height', 'inline-size' and 'block-size' were not
considered to be layout dependent, and thus getComputedStyle could
provide a wrong value.

BUG=849855

TEST=external/wpt/css/css-logical/logical-box-size.html

The test still has some failures because sideways writing modes have not
been implemented yet (http://crbug.com/680331).

Change-Id: I4ee8ed8b2cd575fb3ddd5226b23c6a4bb843b81f
Reviewed-on: https://chromium-review.googlesource.com/1114966
Commit-Queue: Oriol Brufau <obrufau@igalia.com>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570527}
4 files changed