Revert of Add <link rel=next> support to prerender. (https://codereview.chromium.org/113803003/)

Reason for revert:
Linux ASAN Tests (2) run 22831 failed with leaks in the RelNextByFieldTrial test.

Original issue's description:
> Add <link rel=next> support to prerender.
> 
> IEs prerender implementation supports rel=next link elements. Let's
> also parse them, and based on a field trial launch these as
> prerenders.
> 
> R=davidben,tburkard,jochen,jschuh@chromium.org
> BUG=329963
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=250280

TBR=davidben@google.com,jochen@chromium.org,tburkard@chromium.org,davidben@chromium.org,jschuh@chromium.org+,jschuh@chromium.org,gavinp@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=329963

Review URL: https://codereview.chromium.org/145073009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250299 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250299