Revert of Layout children if the width available to them has changed (patchset #3 id:40001 of https://codereview.chromium.org/390633004/)

Reason for revert:
The CL was landed with unrelated changes. Reverting so that the corrected CL can be landed cleanly.

Original issue's description:
> Layout children if the width available to them has changed
> 
> Currently we let a style change to border or padding trigger a layout to
> children, even if the parent's width hasn't changed. This is because the
> change in border/padding alters the amount of space available to the children.
> 
> Likewise if a box has percent padding and uses border-box sizing then the
> space available to children can reduce/increase even when the box itself
> doesn't change size (e.g. because it has a max-width). When that happens we
> still need to relayout its children so they fit to the changed available width.
> 
> If we cached content width or even padding we could watch for changes to this
> available width for children but unfortunately we do neither so both of the
> above cases have to be identified specifically at layout time.
> 
> BUG=391820
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=178864

TBR=jchaffraix@chromium.org
BUG=391820

Review URL: https://codereview.chromium.org/529803002

git-svn-id: svn://svn.chromium.org/blink/trunk@181199 bbb929c8-8fbe-4397-9dbb-9b2b20218538