The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/336b769547264c00d1ac5589a3fe883a3bb2f05e

commit 336b769547264c00d1ac5589a3fe883a3bb2f05e
Author: Eric Willigers <ericwilligers@chromium.org>
Date: Fri Nov 16 10:41:15 2018

CSS: transform-origin specified value without appending 0px

We were previously appending a z value of 0px to the
specified value of transform-origin.

This is not needed, and violates the CSSOM shortest
serialization principle.

It was also inconsistent with our computed value results,
where we don't append a z value of 0px.

Bug:  905997 
Change-Id: I76612a16e2048f568a6215804aa7e11469cb8e29
Reviewed-on: https://chromium-review.googlesource.com/c/1337669
Commit-Queue: Eric Willigers <ericwilligers@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608721}
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/WebKit/LayoutTests/fast/css/transform-inline-style-expected.txt
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/WebKit/LayoutTests/fast/css/transform-inline-style-remove-expected.txt
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/WebKit/LayoutTests/http/tests/devtools/elements/styles-4/svg-style-expected.txt
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/WebKit/LayoutTests/transforms/transform-origin-parsing.html
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/blink/renderer/core/animation/css_transform_origin_interpolation_type.h
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/blink/renderer/core/css/properties/longhands/transform_origin_custom.cc
[modify] https://crrev.com/336b769547264c00d1ac5589a3fe883a3bb2f05e/third_party/blink/renderer/core/css/resolver/style_builder_converter.cc