[errors] de-specialize Transient in favor of Tags.

logdog/server/cmd/logdog_collector/main.go

 // 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 main
 
 import (
         "fmt"
         "time"
 
@@ skipping 173 matching lines @@
         }.Infof(c, "Received Pub/Sub Message.")
 
         startTime := clock.Now(c)
         err := coll.Process(c, msg.Data)
         duration := clock.Now(c).Sub(startTime)
 
         // We track processing time in milliseconds.
         tsTaskProcessingTime.Add(c, duration.Seconds()*1000)
 
         switch {
-        case errors.IsTransient(err):
+        case retry.Tag.In(err):
                 // Do not consume
                 log.Fields{
                         log.ErrorKey: err,
                         "duration":   duration,
                 }.Warningf(c, "TRANSIENT error ingesting Pub/Sub message.")
                 tsPubsubCount.Add(c, 1, "transient_failure")
                 return false
 
         case err == nil:
                 log.Fields{
@@ skipping 18 matching lines @@
 func main() {
         mathrand.SeedRandomly()
         a := application{
                 Service: service.Service{
                         Name:               "collector",
                         DefaultAuthOptions: chromeinfra.DefaultAuthOptions(),
                 },
         }
         a.Run(context.Background(), a.runCollector)
 }