Make HTTP middleware easier to use

common/prpc/talk/buildbot/frontend/prpc.go

Index: common/prpc/talk/buildbot/frontend/prpc.go
diff --git a/common/prpc/talk/buildbot/frontend/prpc.go b/common/prpc/talk/buildbot/frontend/prpc.go
index a3c6f5b1963ddbfd47252d34feb2c793c127c283..c7ee910e68d8a5e4df93d556214bd4a494473d61 100644
--- a/common/prpc/talk/buildbot/frontend/prpc.go
+++ b/common/prpc/talk/buildbot/frontend/prpc.go
@@ -1,22 +1,20 @@
 // Copyright 2016 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package buildbot
 
 import (
-	"github.com/julienschmidt/httprouter"
-
 	"github.com/luci/luci-go/server/discovery"
-	"github.com/luci/luci-go/server/middleware"
 	"github.com/luci/luci-go/server/prpc"
+	"github.com/luci/luci-go/server/router"
 
 	"github.com/luci/luci-go/common/prpc/talk/buildbot/proto"
 )
 
-func InstallAPIRoutes(router *httprouter.Router, base middleware.Base) {
+func InstallAPIRoutes(r *router.Router, base router.MiddlewareChain) {
 	server := &prpc.Server{}
 	buildbot.RegisterBuildbotServer(server, &buildbotService{})
 	discovery.Enable(server)
-	server.InstallHandlers(router, base)
+	server.InstallHandlers(r, base)
 }