Issue 834384  has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7cba16c4aa025ea044d57a5eaceb4d012e13fb93

commit 7cba16c4aa025ea044d57a5eaceb4d012e13fb93
Author: Chris Nardi <cnardi@chromium.org>
Date: Mon May 07 21:19:00 2018

Allow 0% in font-stretch

Per https://github.com/w3c/csswg-drafts/issues/2591, 0% should be an
allowed value in font-stretch. Remove the check that percentages are >=
0 for font-stretch, as any negative non calc values are already rejected
by kValueRangeNonNegative. Also update a test of valid calc values in
font-stretch, as even though they are outside the allowed range, they
should not be subject to parse-time constraints.

Bug:  834236 
Change-Id: I0e728d8cc89b45bac7be956a7662533d4775c511
Reviewed-on: https://chromium-review.googlesource.com/1046926
Commit-Queue: Chris Nardi <cnardi@chromium.org>
Reviewed-by: Dominik Röttsches <drott@chromium.org>
Cr-Commit-Position: refs/heads/master@{#556568}
[modify] https://crrev.com/7cba16c4aa025ea044d57a5eaceb4d012e13fb93/third_party/WebKit/LayoutTests/external/wpt/css/css-fonts/variations/at-font-face-descriptors-expected.txt
[modify] https://crrev.com/7cba16c4aa025ea044d57a5eaceb4d012e13fb93/third_party/WebKit/LayoutTests/external/wpt/css/css-fonts/variations/at-font-face-descriptors.html
[modify] https://crrev.com/7cba16c4aa025ea044d57a5eaceb4d012e13fb93/third_party/WebKit/LayoutTests/external/wpt/css/css-fonts/variations/font-parse-numeric-stretch-style-weight-expected.txt
[modify] https://crrev.com/7cba16c4aa025ea044d57a5eaceb4d012e13fb93/third_party/WebKit/LayoutTests/external/wpt/css/css-fonts/variations/font-stretch-expected.txt
[modify] https://crrev.com/7cba16c4aa025ea044d57a5eaceb4d012e13fb93/third_party/blink/renderer/core/css/properties/css_parsing_utils.cc