Correct offsetLeft and offsetTop calculation for column-span:all.

Correct offsetLeft and offsetTop calculation for column-span:all.

adjustedPositionRelativeTo() handled multicol incorrectly (the calls to
columnOffset()), which was especially hurtful for spanners. We should only call
it on objects in our containing block chain. This means that we need to walk
the ancestry using container() instead of parent(). The container() of a
spanner is the multicol container. We need to skip the inbetween flow thread,
since it only contains column content, and not spanners.

We also had bugs here with absolutely positioned objects inside multicol
containers whose containing block are on the outside of the multicol container,
but that's not really going to matter until we're able to lay out such objects
correctly. That's bug 291616. As such, this CL is also a preparatory patch for
fixing that bug.

This CL will also make it possible to write check-layout.js tests for spanners,
instead of having to resort to reftest or something even lesser.

BUG=563446
Committed: https://crrev.com/1d341dd82cbcc6e2a67414a7fd358c4abeb56ca4
Cr-Commit-Position: refs/heads/master@{#412255}

[mstensho (USE GERRIT), 2016-08-15 19:43:38]

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

[commit-bot: I haz the power, 2016-08-15 19:44:01]

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, 2016-08-15 20:53:42]

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

[commit-bot: I haz the power, 2016-08-15 20:53:42]

Dry run: Try jobs failed on following builders:
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[mstensho (USE GERRIT), 2016-08-16 08:21:31]

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

[commit-bot: I haz the power, 2016-08-16 08:21:45]

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, 2016-08-16 10:31:56]

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

[commit-bot: I haz the power, 2016-08-16 10:31:57]

Dry run: Try jobs failed on following builders:
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[mstensho (USE GERRIT), 2016-08-16 10:40:23]

mstensho@opera.com changed reviewers:
+ eae@chromium.org

[eae, 2016-08-16 14:43:36]

LGTM

[eae, 2016-08-16 14:43:41]

The CQ bit was checked by eae@chromium.org

[commit-bot: I haz the power, 2016-08-16 14:44:04]

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, 2016-08-16 15:57:15]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-08-16 15:59:47]

Description was changed from

==========
Correct offsetLeft and offsetTop calculation for column-span:all.

adjustedPositionRelativeTo() handled multicol incorrectly (the calls to
columnOffset()), which was especially hurtful for spanners. We should only call
it on objects in our containing block chain. This means that we need to walk
the ancestry using container() instead of parent(). The container() of a
spanner is the multicol container. We need to skip the inbetween flow thread,
since it only contains column content, and not spanners.

We also had bugs here with absolutely positioned objects inside multicol
containers whose containing block are on the outside of the multicol container,
but that's not really going to matter until we're able to lay out such objects
correctly. That's bug 291616. As such, this CL is also a preparatory patch for
fixing that bug.

This CL will also make it possible to write check-layout.js tests for spanners,
instead of having to resort to reftest or something even lesser.

BUG=563446
==========

to

==========
Correct offsetLeft and offsetTop calculation for column-span:all.

adjustedPositionRelativeTo() handled multicol incorrectly (the calls to
columnOffset()), which was especially hurtful for spanners. We should only call
it on objects in our containing block chain. This means that we need to walk
the ancestry using container() instead of parent(). The container() of a
spanner is the multicol container. We need to skip the inbetween flow thread,
since it only contains column content, and not spanners.

We also had bugs here with absolutely positioned objects inside multicol
containers whose containing block are on the outside of the multicol container,
but that's not really going to matter until we're able to lay out such objects
correctly. That's bug 291616. As such, this CL is also a preparatory patch for
fixing that bug.

This CL will also make it possible to write check-layout.js tests for spanners,
instead of having to resort to reftest or something even lesser.

BUG=563446

Committed: https://crrev.com/1d341dd82cbcc6e2a67414a7fd358c4abeb56ca4
Cr-Commit-Position: refs/heads/master@{#412255}
==========

[commit-bot: I haz the power, 2016-08-16 15:59:48]

Patchset 2 (id:??) landed as
https://crrev.com/1d341dd82cbcc6e2a67414a7fd358c4abeb56ca4
Cr-Commit-Position: refs/heads/master@{#412255}