Merge 2840: Fix when orthogonal writing mode roots have floating siblings

Merge 2840: Fix when orthogonal writing mode roots have floating siblings

When orthogonal writing mode roots have floating siblings, its
containing block may still have old or even deleted LayoutObjects.
This occurs when LayoutMultiColumnFlowThread::populate(),
LayoutBoxModelObject::moveChildrenTo() with !fullRemoveInsert,
or more, for the optimization purposes.

This patch clears such objects to be re-created when the containing
block is laid out.

BUG=604095, 633409, 646178
Review-Url: https://codereview.chromium.org/2025543002
Cr-Commit-Position: refs/heads/master@{#419376}
(cherry picked from commit 5c43382692e6b687373576984181e52c30ccd142)

Committed: https://chromium.googlesource.com/chromium/src/+/f0a010e317a1043e7faf7160f6d2afb760d6f1f5

[kojii, 2016-09-20 13:14:56]

Description was changed from

==========
Merge 2840: Fix when orthogonal writing mode roots have floating siblings

When orthogonal writing mode roots have floating siblings, its
containing block may still have old or even deleted LayoutObjects.
This occurs when LayoutMultiColumnFlowThread::populate(),
LayoutBoxModelObject::moveChildrenTo() with !fullRemoveInsert,
or more, for the optimization purposes.

This patch clears such objects to be re-created when the containing
block is laid out.

BUG=604095, 633409, 646178

Review-Url: https://codereview.chromium.org/2025543002
Cr-Commit-Position: refs/heads/master@{#419376}
(cherry picked from commit 5c43382692e6b687373576984181e52c30ccd142)
==========

to

==========
Merge 2840: Fix when orthogonal writing mode roots have floating siblings

When orthogonal writing mode roots have floating siblings, its
containing block may still have old or even deleted LayoutObjects.
This occurs when LayoutMultiColumnFlowThread::populate(),
LayoutBoxModelObject::moveChildrenTo() with !fullRemoveInsert,
or more, for the optimization purposes.

This patch clears such objects to be re-created when the containing
block is laid out.

BUG=604095, 633409, 646178

Review-Url: https://codereview.chromium.org/2025543002
Cr-Commit-Position: refs/heads/master@{#419376}
(cherry picked from commit 5c43382692e6b687373576984181e52c30ccd142)

Committed:
https://chromium.googlesource.com/chromium/src/+/f0a010e317a1043e7faf7160f6d2...
==========

[kojii, 2016-09-20 13:15:00]

Committed patchset #1 (id:1) manually as
f0a010e317a1043e7faf7160f6d2afb760d6f1f5.