Implement Layout Containment

Implement Layout Containment

Layout containment provides a guarantee that an element's subtree will
not escape its bounds in a layout-impactful way. This means that the
element's descendants don't impact its size, so it collapses away
when the size isn't specified. It also creates a formatting context.

Layout Containment description from spec:
https://drafts.csswg.org/css-containment/#containment-layout

Intent to implement:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/9W80Kw-z3ss
BUG=561713
Committed: https://crrev.com/b66c49fa179e76970cc9cf4500fee1f9f0ff2cb8
Cr-Commit-Position: refs/heads/master@{#378906}

[leviw_travelin_and_unemployed, 2015-12-16 22:19:50]

leviw@chromium.org changed reviewers:
+ eae@chromium.org, esprehn@chromium.org, ojan@chromium.org, szager@chromium.org

[szager1, 2015-12-16 23:46:23]

https://codereview.chromium.org/1530303003/diff/1/third_party/WebKit/LayoutTe...
File
third_party/WebKit/LayoutTests/fast/css/containment/layout-containment-sizing.html
(right):

https://codereview.chromium.org/1530303003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/fast/css/containment/layout-containment-sizing.html:44:
<div id="absolute">
Might be a good idea to do another test case like this:

<div id="absolute">
  <div class="overhangingFloat"></div>
  <div class="containLayout sized inlineBlock" data-offset-x=10></div>
</div>

[leviw_travelin_and_unemployed, 2015-12-17 00:04:35]

On 2015/12/16 at 23:46:23, szager wrote:
>
https://codereview.chromium.org/1530303003/diff/1/third_party/WebKit/LayoutTe...
> File
third_party/WebKit/LayoutTests/fast/css/containment/layout-containment-sizing.html
(right):
> 
>
https://codereview.chromium.org/1530303003/diff/1/third_party/WebKit/LayoutTe...
>
third_party/WebKit/LayoutTests/fast/css/containment/layout-containment-sizing.html:44:
<div id="absolute">
> Might be a good idea to do another test case like this:
> 
> <div id="absolute">
>   <div class="overhangingFloat"></div>
>   <div class="containLayout sized inlineBlock" data-offset-x=10></div>
> </div>

Good call! PTAL

[szager1, 2015-12-18 17:20:09]

lgtm

[ojan, 2015-12-18 18:21:14]

lgtm

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/LayoutBlock.cpp (right):

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/LayoutBlock.cpp:2248: if
((!style()->isOverflowVisible() &&
!shouldIgnoreOverflowPropertyForInlineBlockBaseline()) ||
style()->containsLayout()) {
I think this is the right behavior, although I'm not confident the current spec
covers this. Might want to run this by Tab. If this is handled by the current
spec, I think it at least deserves an explanatory note.

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/LayoutBox.cpp (right):

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/LayoutBox.cpp:2382: if
(style()->containsLayout())
Nit: I might have written this as:
LayoutUnit height = style()->containsLayout() ? borderAndPaddingLogicalHeight()
: logicalHeight();
computeLogicalHeight(height, logicalTop(), computedValues);

Avoids duplicating a bit of code.

[leviw_travelin_and_unemployed, 2016-01-12 19:36:30]

leviw@chromium.org changed reviewers:
+ tabatkins@chromium.org

[leviw_travelin_and_unemployed, 2016-01-12 19:36:31]

Tab, ptal at the comment regarding baselines for inline-blocks with contain:
layout.

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/layout/LayoutBlock.cpp (right):

https://codereview.chromium.org/1530303003/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/layout/LayoutBlock.cpp:2248: if
((!style()->isOverflowVisible() &&
!shouldIgnoreOverflowPropertyForInlineBlockBaseline()) ||
style()->containsLayout()) {
On 2015/12/18 at 18:21:14, ojan wrote:
> I think this is the right behavior, although I'm not confident the current
spec covers this. Might want to run this by Tab. If this is handled by the
current spec, I think it at least deserves an explanatory note.

I did add some info to the above comment to try and tackle this. My feeling was
the spec does cover this, albeit obliquely. It says the contents shouldn't
effect layout, and this ensures that's the case, and that's what I tried to
elude to. +tabatkins to comment.

[esprehn, 2016-02-10 10:23:16]

I think you need to ping tab directly, he's bad at @chromium.org emails.

[leviw_travelin_and_unemployed, 2016-02-12 02:20:57]

On 2016/02/10 at 10:23:16, esprehn wrote:
> I think you need to ping tab directly, he's bad at @chromium.org emails.

Yeah, I did, but I think he missed it because he was on vacation :p I'll ping
him again!

[leviw_travelin_and_unemployed, 2016-03-02 23:35:13]

The CQ bit was checked by leviw@chromium.org

[leviw_travelin_and_unemployed, 2016-03-02 23:35:13]

I chatted with Tab. On the baseline issue: "Yes, I agree.  I'll specify that."

We also talked about overflow and I'll be following up on that issue in a
separate patch.

[leviw_travelin_and_unemployed, 2016-03-02 23:35:14]

The patchset sent to the CQ was uploaded after l-g-t-m from ojan@chromium.org,
szager@chromium.org
Link to the patchset: https://codereview.chromium.org/1530303003/#ps80001
(title: "Switch to Ahem.")

[commit-bot: I haz the power, 2016-03-02 23:35:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1530303003/80001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1530303003/80001

[commit-bot: I haz the power, 2016-03-03 01:30:22]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2016-03-03 01:31:50]

Description was changed from

==========
Implement Layout Containment

Layout containment provides a guarantee that an element's subtree will
not escape its bounds in a layout-impactful way. This means that the
element's descendants don't impact its size, so it collapses away
when the size isn't specified. It also creates a formatting context.

Layout Containment description from spec:
https://drafts.csswg.org/css-containment/#containment-layout

Intent to implement:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/9W80Kw-z3ss
BUG=561713
==========

to

==========
Implement Layout Containment

Layout containment provides a guarantee that an element's subtree will
not escape its bounds in a layout-impactful way. This means that the
element's descendants don't impact its size, so it collapses away
when the size isn't specified. It also creates a formatting context.

Layout Containment description from spec:
https://drafts.csswg.org/css-containment/#containment-layout

Intent to implement:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/9W80Kw-z3ss
BUG=561713

Committed: https://crrev.com/b66c49fa179e76970cc9cf4500fee1f9f0ff2cb8
Cr-Commit-Position: refs/heads/master@{#378906}
==========

[commit-bot: I haz the power, 2016-03-03 01:31:51]

Patchset 5 (id:??) landed as
https://crrev.com/b66c49fa179e76970cc9cf4500fee1f9f0ff2cb8
Cr-Commit-Position: refs/heads/master@{#378906}