CSS Motion Path: offset-position,offset-path establish stacking context

CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property

BUG=648113
Committed: https://crrev.com/40c7b346c56c248c7337bfb33d46517439a0740f
Cr-Commit-Position: refs/heads/master@{#421767}

[Eric Willigers, 2016-09-27 00:59:45]

The CQ bit was checked by ericwilligers@chromium.org to run a CQ dry run

[Eric Willigers, 2016-09-27 01:00:05]

ericwilligers@chromium.org changed reviewers:
+ suzyh@chromium.org

[commit-bot: I haz the power, 2016-09-27 01:00:40]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-27 02:46:47]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-27 02:46:48]

Dry run: This issue passed the CQ dry run.

[suzyh_UTC10 (ex-contributor), 2016-09-27 03:49:10]

I'm OK with this, but have not dealt with stacking contexts at all before, so
would feel happier if this review went to someone else.

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html (right):

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:4: <section
id="container" style="will-change: transform">
What is the purpose of "will-change: transform" here? My guess is that it
creates a stacking context that makes the rest of the test work, but if the
offset-* properties are supposed to create a stacking context anyway, is this
necessary?

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:24:
assert_equals(document.getElementById("s1").offsetParent,
document.getElementById("d1"));
Aside: Wow, offsetParent is a confusing name in this context. offsetParent is to
do with stacking contexts, right, and has nothing in particular to do with
offset path?

[Eric Willigers, 2016-09-27 04:34:07]

Description was changed from

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.


BUG=648113
==========

to

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property


BUG=648113
==========

[Eric Willigers, 2016-09-27 04:34:07]

ericwilligers@chromium.org changed reviewers:
+ dstockwell@chromium.org

[Eric Willigers, 2016-09-27 04:34:28]

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html (right):

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:4: <section
id="container" style="will-change: transform">
On 2016/09/27 03:49:10, suzyh wrote:
> What is the purpose of "will-change: transform" here? My guess is that it
> creates a stacking context that makes the rest of the test work, but if the
> offset-* properties are supposed to create a stacking context anyway, is this
> necessary?

It is for the last three tests. offset-distance, offset-rotation, offset-anchor
do not themselves introduce a transform-like effect. So the last three tests
don't have d3/d4/d5 as the offsetParent. I could have used "transform: 0deg" or
something similar to force #container to be the result. Alternately, I could
wrap the test in <body> </body>, and document.body would have been the
offsetParent for the last three tests.

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:24:
assert_equals(document.getElementById("s1").offsetParent,
document.getElementById("d1"));
On 2016/09/27 03:49:10, suzyh wrote:
> Aside: Wow, offsetParent is a confusing name in this context. offsetParent is
to
> do with stacking contexts, right, and has nothing in particular to do with
> offset path?

Agreed. Confusing name.
https://drafts.csswg.org/cssom-view/#dom-htmlelement-offsetparent

[suzyh_UTC10 (ex-contributor), 2016-09-28 01:21:59]

suzyh@chromium.org changed reviewers:
- suzyh@chromium.org

[Eric Willigers, 2016-09-29 04:45:08]

ericwilligers@chromium.org changed reviewers:
+ sashab@chromium.org

[sashab, 2016-09-29 04:47:37]

LGTM

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html (right):

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:27:
assert_equals(document.getElementById("s2").offsetParent,
document.getElementById("d2"));
Just use s2, d2 etc instead of getElementById.

[Eric Willigers, 2016-09-29 05:07:30]

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
File third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html (right):

https://codereview.chromium.org/2369143003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/css3/motion-path/offsetParent.html:27:
assert_equals(document.getElementById("s2").offsetParent,
document.getElementById("d2"));
On 2016/09/29 04:47:37, sashab wrote:
> Just use s2, d2 etc instead of getElementById.

Done.

[dstockwell, 2016-09-29 05:28:23]

lgtm

[Eric Willigers, 2016-09-29 05:40:48]

The CQ bit was checked by ericwilligers@chromium.org

[Eric Willigers, 2016-09-29 05:40:48]

The patchset sent to the CQ was uploaded after l-g-t-m from sashab@chromium.org
Link to the patchset: https://codereview.chromium.org/2369143003/#ps20001
(title: "concise")

[commit-bot: I haz the power, 2016-09-29 05:40:57]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-29 07:08:59]

Description was changed from

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property


BUG=648113
==========

to

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property


BUG=648113
==========

[commit-bot: I haz the power, 2016-09-29 07:09:00]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-29 07:10:22]

Description was changed from

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property


BUG=648113
==========

to

==========
CSS Motion Path: offset-position,offset-path establish stacking context

When offset-path or offset-position are not their initial values,
a stacking context is created. Similarly, a stacking context is
created when either is mentioned by will-change.

https://drafts.fxtf.org/motion-1/#offset-path-property
https://drafts.fxtf.org/motion-1/#offset-position-property

BUG=648113

Committed: https://crrev.com/40c7b346c56c248c7337bfb33d46517439a0740f
Cr-Commit-Position: refs/heads/master@{#421767}
==========

[commit-bot: I haz the power, 2016-09-29 07:10:23]

Patchset 2 (id:??) landed as
https://crrev.com/40c7b346c56c248c7337bfb33d46517439a0740f
Cr-Commit-Position: refs/heads/master@{#421767}