Revert 164241 "Add support for rel=next to Prerender in Blink."

Seems to cause Chrome crashes during several perf benchmarks.

BUG=330820

> Add support for rel=next to Prerender in Blink.
> 
> <link rel=next ...> elements are also used to drive prerenders. Let's
> parse them and pass them up to our embedder.
> 
> BUG=329963
> R=japhet@chromium.org,abarth,tburkard,davidben,jochen
> 
> Review URL: https://codereview.chromium.org/116183005

TBR=gavinp@chromium.org

Review URL: https://codereview.chromium.org/105763004

git-svn-id: svn://svn.chromium.org/blink/trunk@164596 bbb929c8-8fbe-4397-9dbb-9b2b20218538