The same applies to the Content Distribution properties (align-content and justify-content) 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/db99fa6fc1d16bfc187b539f06d947ef04fae8b5

commit db99fa6fc1d16bfc187b539f06d947ef04fae8b5
Author: Javier Fernandez <jfernandez@igalia.com>
Date: Fri Jan 19 03:17:33 2018

[css-align] overflow-position keyword must have a fixed position

There were several discussions to avoid ambiguities with the complex
values, specially when it comes to define the place-xxx shorthands.

One of the sources of problems is the 'overflow-position' keyword. The
CSS WG has decided to change the syntax of all the CSS Box Alignment
properties so that the 'overflow-position' keyword always precede the
'self-position' or the 'content-position' keywords.

https://github.com/w3c/csswg-drafts/issues/1446#event-1125715434

In order to apply this change to the Content Distribution properties'
(align-content and justify-content) syntax I had to completely
re-implement their parsing function. Thanks to this I addressed also
the issue with the content-distribution fallback, which cannot be
specified explicitly now.

https://github.com/w3c/csswg-drafts/issues/1002#ref-commit-c38cac4

Bug:  802098 ,  802247 
Change-Id: I57315a475940c00d0c0dafbb4f1b32a2c6c1ff68
Reviewed-on: https://chromium-review.googlesource.com/868531
Commit-Queue: Javier Fernandez <jfernandez@igalia.com>
Reviewed-by: meade_UTC10 <meade@chromium.org>
Reviewed-by: Manuel Rego Casasnovas <rego@igalia.com>
Cr-Commit-Position: refs/heads/master@{#530416}
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/TestExpectations
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-align-content-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-align-content-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-align-content-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-align-content-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-align-content-005.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-justify-content-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-justify-content-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-justify-content-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-justify-content-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/content-distribution/parse-justify-content-005.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-align-items-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-align-items-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-align-items-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-align-items-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-align-items-005.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-005.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/default-alignment/parse-justify-items-006.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/resources/alignment-parsing-utils.js
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-align-self-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-align-self-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-align-self-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-align-self-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-align-self-005.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-justify-self-001.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-justify-self-002.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-justify-self-003.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-justify-self-004.html
[add] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-align/self-alignment/parse-justify-self-005.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-grid/abspos/grid-positioned-items-content-alignment-001.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/external/wpt/css/css-grid/abspos/grid-positioned-items-content-alignment-rtl-001.html
[delete] https://crrev.com/bb464442d16fad8ecd32edb189f66709a5c7a5ad/third_party/WebKit/LayoutTests/external/wpt/css/css-grid/support/grid-alignment.css
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[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/overwrite-content-alignment-expected.txt
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/overwrite-content-alignment.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/overwrite-self-alignment-expected.txt
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[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/parse-align-self.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/parse-justify-content.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/parse-justify-items.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/alignment/parse-justify-self.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/fast/css-grid-layout/resources/grid-alignment.css
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/align-items-overflow-change-expected.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/align-items-overflow-change.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/align-self-overflow-change-expected.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/align-self-overflow-change.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/justify-items-overflow-change-expected.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/justify-items-overflow-change.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/justify-self-overflow-change-expected.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/LayoutTests/paint/invalidation/overflow/justify-self-overflow-change.html
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/Source/core/css/CSSContentDistributionValue.cpp
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/Source/core/css/properties/CSSParsingUtils.cpp
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/Source/core/css/properties/ComputedStyleUtils.cpp
[modify] https://crrev.com/db99fa6fc1d16bfc187b539f06d947ef04fae8b5/third_party/WebKit/Source/core/css/resolver/StyleBuilderConverter.cpp

This issue should be FIXED now.