Revert "Consider floats as HitTest candidate for selection"

This reverts commit ebf3a5282adcb4eaa862516508517d57ae052009.

Reason for revert: This change caused a regression in how caret is positioned in contenteditable areas with floats or multicolumns. 

Original change's description:
> Consider floats as HitTest candidate for selection
> 
> Selection with floats has a weird and unpredictable behavior. The root
> cause is that floats are not considered valid HitTest candidates.
> 
> There are many other cases where float elements are ignored when
> traversing the tree looking for the closes element to a specific
> LayoutPoint.
> 
> This patch address just one of this cases, where floats are children
> of a in-flow block-level box.
> 
> Bug: 758526
> Change-Id: I918af3ee21aa1070fa03a9fe1073205cc0a57300
> Reviewed-on: https://chromium-review.googlesource.com/643106
> Reviewed-by: Philip Rogers (OOO) <pdr@chromium.org>
> Commit-Queue: Javier Fernandez <jfernandez@igalia.com>
> Cr-Commit-Position: refs/heads/master@{#523410}

TBR=yosin@chromium.org,pdr@chromium.org,jfernandez@igalia.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 758526, 888424
Change-Id: Iba0f1641eeae63a52ef914b334cb302e69b7e7d9
Reviewed-on: https://chromium-review.googlesource.com/c/1271102
Reviewed-by: Philip Rogers <pdr@chromium.org>
Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Javier Fernandez <jfernandez@igalia.com>
Commit-Queue: Javier Fernandez <jfernandez@igalia.com>
Cr-Commit-Position: refs/heads/master@{#609248}
2 files changed