commit 80f6578864d46f8545ffbbafa1d6f73478c2e23c
author Chris Harrelson <chrishtr@chromium.org> Wed Aug 01 01:41:16 2018
committer Commit Bot <commit-bot@chromium.org> Wed Aug 01 01:41:16 2018
tree 349f06c415f58ee7e546e34078f7d27b195454eb
parent 274bfa5ec8853bfa1232259e8f45a47be4ac206c

Account for float under positioned inline when computing offsets.

The containing block of a float is the containing *block*,
meaning that it is an actual block and therefore does not include
inlines. This means that floats and positioned elements can have
mutually inconsistent containing block chains. Example:

<div id=root>
  <span style='position: relative'>
    <div style='float: left'>
       <span style='position: absolute'></span>
    </div>
  </span>
</div>

In this example, the containing block of the abs-pos span
is the rel-pos span. However, the containing block of the float
is the root element. Therefore the containing block chains
mutually cross each other.

Other than floats, containing blocks do not have this behavior.
IOW if there are no floats, and ContainingBlock(A) = B, then
for any element C between A and B in the DOM parent chain, B is
in its containing block chain.

Bug: 823748

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I4038aa6db33af53b04721760d6ee32904ac7a727
Reviewed-on: https://chromium-review.googlesource.com/1156136
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579662}