Make HTTP middleware easier to use

appengine/cmd/logdog_coordinator/backend/main.go

 // Copyright 2015 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 module
 
 import (
         "net/http"
 
         "golang.org/x/net/context"
 
-        "github.com/julienschmidt/httprouter"
         "github.com/luci/luci-go/appengine/logdog/coordinator"
         "github.com/luci/luci-go/appengine/logdog/coordinator/config"
         "github.com/luci/luci-go/appengine/tumble"
+        "github.com/luci/luci-go/server/router"
 
         // Include mutations package so its Mutations will register with tumble via
         // init().
         _ "github.com/luci/luci-go/appengine/logdog/coordinator/mutations"
 )
 
 func init() {
         tmb := tumble.Service{
                 Middleware: func(c context.Context) context.Context {
                         if err := config.UseConfig(&c); err != nil {
                                 panic(err)
                         }
                         c = coordinator.UseProdServices(c)
                         return c
                 },
         }
 
-        router := httprouter.New()
-        tmb.InstallHandlers(router)
+        r := router.New()
+        tmb.InstallHandlers(r)
 
-        http.Handle("/", router)
+        http.Handle("/", r)
 }