Revert 241144 "Implement chromium's TLS."

> Implement chromium's TLS.
> 
> Using one system TLS to implement multiple chrome's TLS slots.
> 
> BUG=264406
> 
> Review URL: https://codereview.chromium.org/60743004

BUG=329121
TBR=michaelbai@chromium.org

Review URL: https://codereview.chromium.org/108793004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241152 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241152