Establish a list marker's offset before floats have been added to its line
Computing the offset for a list marker after the rest of the objects on the line
it is on have been laid out means it will avoid floats it ought not to.
Instead, compute the offset when laying out the marker and cache it for use later.
BUG=
548616
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Committed:
https://crrev.com/c896e79e5ba348d7ed87438cd3a19d0176f3036d
Cr-Commit-Position: refs/heads/master@{#437798}