Revert of Strip anonymous blocks when change in style removes need for them (https://codereview.chromium.org/253313005/)

Reason for revert:
Caused an incorrect cast in RenderBlockFlow.

TBR=inferno@chromium.org,eae@chromium.org
BUG=387211

Original issue's description:
> Strip anonymous blocks when change in style removes need for them
> 
> When a block element becomes a float or out of flow we should strip
> any anonymous blocks wrapping its inline siblings.
> 
> BUG=331251
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175220

Review URL: https://codereview.chromium.org/349103002

git-svn-id: svn://svn.chromium.org/blink/trunk@176779 bbb929c8-8fbe-4397-9dbb-9b2b20218538