Revert 165976 "Make RenderObject::adjustStyleDifference abort ea..."

> Make RenderObject::adjustStyleDifference abort early for Text (and make the function more clear)
> 
> This function had a bunch of confusing cases in it, lets start by making
> it clear that for Text we don't need to do most of the work. I also switched
> to using <= instead of < for a bunch of cases to make it more obvious what
> conditions this code is for.
> 
> BUG=335703
> 
> Review URL: https://codereview.chromium.org/148463012

TBR=esprehn@chromium.org

Review URL: https://codereview.chromium.org/150693003

git-svn-id: svn://svn.chromium.org/blink/trunk@166177 bbb929c8-8fbe-4397-9dbb-9b2b20218538