Revert of Remove some duplicated code when accounting for floats at line-end

Revert of Remove some duplicated code when accounting for floats at line-end (patchset #1 id:1 of https://codereview.chromium.org/1152953002/)

Reason for revert:
Together with https://codereview.chromium.org/1132103007 caused issues with layout identified in crbug.com/498664. Reverting both patches.

Original issue's description:
> Remove some duplicated code when accounting for floats at line-end
> 
> This results in less code, but not that much less. The real win is in moving the
> quite cumbersome logic to a place where it's not obscuring the purpose of the
> functions it lives in.
> 
> BUG=487775
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196012

TBR=leviw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=487775
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196888

[rhogan, 2015-06-10 18:25:26]

Created Revert of Remove some duplicated code when accounting for floats at
line-end

[commit-bot: I haz the power, 2015-06-10 18:25:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1174053003/1

[commit-bot: I haz the power, 2015-06-10 18:26:10]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196888