Old lines may be detached / extracted during layout.

Old lines may be detached / extracted during layout.

Back out over-simplified code from https://codereview.chromium.org/1915803004/

Since lines from an old layout pass that haven't yet been relaid out may not be
in the line box list at all at some given point during layout, lastRootBox()
didn't work as expected. It would either return the wrong last-line, or even
nullptr.

BUG=607451
Committed: https://crrev.com/7c96d3817765ae0d848bdf2962c7cc1c52384848
Cr-Commit-Position: refs/heads/master@{#390508}

[mstensho (USE GERRIT), 2016-04-28 11:37:47]

mstensho@opera.com changed reviewers:
+ eae@chromium.org, leviw@chromium.org, szager@chromium.org,
wkorman@chromium.org

[mstensho (USE GERRIT), 2016-04-28 11:37:47]

https://www.youtube.com/watch?v=tcGQpjCztgA

[szager1, 2016-04-28 17:36:10]

lgtm

[mstensho (USE GERRIT), 2016-04-28 20:20:15]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2016-04-28 20:20:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1927913002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1927913002/1

[commit-bot: I haz the power, 2016-04-28 21:02:29]

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

[commit-bot: I haz the power, 2016-04-28 21:02:30]

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

[mstensho (USE GERRIT), 2016-04-28 21:05:51]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2016-04-28 21:06:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1927913002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1927913002/1

[commit-bot: I haz the power, 2016-04-28 22:25:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-30 17:22:04]

Patchset 1 (id:??) landed as
https://crrev.com/7c96d3817765ae0d848bdf2962c7cc1c52384848
Cr-Commit-Position: refs/heads/master@{#390508}

[commit-bot: I haz the power, 2016-04-30 17:57:59]

Description was changed from

==========
Old lines may be detached / extracted during layout.

Back out over-simplified code from https://codereview.chromium.org/1915803004/

Since lines from an old layout pass that haven't yet been relaid out may not be
in the line box list at all at some given point during layout, lastRootBox()
didn't work as expected. It would either return the wrong last-line, or even
nullptr.

BUG=607451
==========

to

==========
Old lines may be detached / extracted during layout.

Back out over-simplified code from https://codereview.chromium.org/1915803004/

Since lines from an old layout pass that haven't yet been relaid out may not be
in the line box list at all at some given point during layout, lastRootBox()
didn't work as expected. It would either return the wrong last-line, or even
nullptr.

BUG=607451

Committed: https://crrev.com/7c96d3817765ae0d848bdf2962c7cc1c52384848
Cr-Commit-Position: refs/heads/master@{#390508}
==========