Compute better reference/visual boxes for clip-path in columns

Compute better reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/a73f1b21656e5e08eaca11b038770d166fc3fcd7
Cr-Commit-Position: refs/heads/master@{#416451}

[fs, 2016-09-02 12:16:09]

Description was changed from

==========
Compute correct reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
==========

to

==========
Compute correct reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[fs, 2016-09-02 12:16:14]

The CQ bit was checked by fs@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2016-09-02 12:16:30]

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

[fs, 2016-09-02 13:19:37]

fs@opera.com changed reviewers:
+ mstensho@opera.com

[commit-bot: I haz the power, 2016-09-02 14:55:51]

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

[commit-bot: I haz the power, 2016-09-02 14:55:52]

Dry run: This issue passed the CQ dry run.

[mstensho (USE GERRIT), 2016-09-02 19:06:01]

https://codereview.chromium.org/2300383002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp (right):

https://codereview.chromium.org/2300383002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp:272:
m_paintLayer.convertFromFlowThreadToVisualBoundingBoxInAncestor(paintingInfo.rootLayer,
referenceBox);
This isn't going to work correctly if the clipping path crosses column
boundaries, right? You'll then slice the clip box into multiple fragments and
use the union of those fragments as referenceBox.

I'd expect to see no red here, for instance.

<div style="columns:2; width:300px; background:yellow;">
    <div style="height:300px; border:5px solid red;
-webkit-clip-path:inset(5px); background:lime;"></div>
</div>

I guess the only way to fix this is to apply clip-path AFTER fragmentation.
Could you add a note about this?

[fs, 2016-09-02 19:16:51]

https://codereview.chromium.org/2300383002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp (right):

https://codereview.chromium.org/2300383002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp:272:
m_paintLayer.convertFromFlowThreadToVisualBoundingBoxInAncestor(paintingInfo.rootLayer,
referenceBox);
On 2016/09/02 at 19:06:01, mstensho wrote:
> This isn't going to work correctly if the clipping path crosses column
boundaries, right? You'll then slice the clip box into multiple fragments and
use the union of those fragments as referenceBox.

Yeah, we have similar issues with inlines spanning multiple lines. 

> I'd expect to see no red here, for instance.
> 
> <div style="columns:2; width:300px; background:yellow;">
>     <div style="height:300px; border:5px solid red;
-webkit-clip-path:inset(5px); background:lime;"></div>
> </div>
> 
> I guess the only way to fix this is to apply clip-path AFTER fragmentation.
Could you add a note about this?

Added note.

[mstensho (USE GERRIT), 2016-09-02 19:44:09]

lgtm

https://codereview.chromium.org/2300383002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp (right):

https://codereview.chromium.org/2300383002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp:272: // determined
per-fragment, and hence this ought to be perform after fragmentation.
*performed

[fs, 2016-09-02 20:11:07]

The CQ bit was checked by fs@opera.com to run a CQ dry run

[commit-bot: I haz the power, 2016-09-02 20:11:38]

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

[fs, 2016-09-02 20:12:01]

https://codereview.chromium.org/2300383002/diff/20001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp (right):

https://codereview.chromium.org/2300383002/diff/20001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp:272: // determined
per-fragment, and hence this ought to be perform after fragmentation.
On 2016/09/02 at 19:44:09, mstensho wrote:
> *performed

Fixed, thanks.

[fs, 2016-09-02 20:54:24]

Description was changed from

==========
Compute correct reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Compute better reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[commit-bot: I haz the power, 2016-09-02 23:56:12]

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

[commit-bot: I haz the power, 2016-09-02 23:56:13]

Dry run: This issue passed the CQ dry run.

[fs, 2016-09-03 08:02:22]

The CQ bit was checked by fs@opera.com

[fs, 2016-09-03 08:02:23]

The patchset sent to the CQ was uploaded after l-g-t-m from mstensho@opera.com
Link to the patchset: https://codereview.chromium.org/2300383002/#ps40001
(title: "performed")

[commit-bot: I haz the power, 2016-09-03 08:02:31]

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, 2016-09-03 08:06:10]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-09-03 08:08:24]

Description was changed from

==========
Compute better reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Compute better reference/visual boxes for clip-path in columns

clip-path's are applied before fragmentation, which means that we need
to adjust the coordinate space for the clip-path and its reference box
"manually" to get the correct visual coordinate space.

Also fix the origin used for clip-path to be the top-left corner of the
reference box. This only applies when SVG <clipPath> elements with
clipPathUnits='userSpaceOnUse' is referenced.

BUG=626097
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Committed: https://crrev.com/a73f1b21656e5e08eaca11b038770d166fc3fcd7
Cr-Commit-Position: refs/heads/master@{#416451}
==========

[commit-bot: I haz the power, 2016-09-03 08:08:25]

Patchset 3 (id:??) landed as
https://crrev.com/a73f1b21656e5e08eaca11b038770d166fc3fcd7
Cr-Commit-Position: refs/heads/master@{#416451}