This reverts commit 8b5b5941.

Reason for revert: nothing wrong with this CL, but implementing a manual roll to build.git takes more than 20 min. I will reland this CL once my roll to build.git CL is ready

Original change's description:
> add "generic" infra path config
> 
> It proved to be dangerous to introduce conditional logic into recipes
> and recipe modules to alternate between buildbot and luci modes, namely
> it touches buildbot code paths, which can be very dangerous.
> 
> Instead, introduce "generic" default path config that configures
> existing base paths from the built-in ones.
> 
> Also remove swarmbucket path config because it is not used.
> 
> R=​iannucci@chromium.org
> BUG=660481
> 
> Change-Id: Ide0e1f64913fe35766b997ab5b55f01f4c63aa58
> Reviewed-on: https://chromium-review.googlesource.com/459234
> Commit-Queue: Nodir Turakulov <nodir@chromium.org>
> Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
> 

TBR=iannucci@chromium.org,nodir@chromium.org,chromium-reviews@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=660481

Change-Id: If27a537689dfe3669015bcbc7a5f07ca1f5c10af
Reviewed-on: https://chromium-review.googlesource.com/461223Reviewed-by: Nodir Turakulov <nodir@chromium.org>
Commit-Queue: Nodir Turakulov <nodir@chromium.org>