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

common/auth/auth_test.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 auth
 
 import (
-        "fmt"
         "io/ioutil"
         "math/rand"
         "net/http"
         "net/http/httptest"
         "testing"
         "time"
 
         "golang.org/x/net/context"
         "golang.org/x/oauth2"
 
         "github.com/luci/luci-go/common/auth/internal"
         "github.com/luci/luci-go/common/clock"
         "github.com/luci/luci-go/common/clock/testclock"
         "github.com/luci/luci-go/common/data/rand/mathrand"
         "github.com/luci/luci-go/common/errors"
+        "github.com/luci/luci-go/common/retry"
 
         . "github.com/luci/luci-go/common/testing/assertions"
         . "github.com/smartystreets/goconvey/convey"
 )
 
 var (
         now    = time.Date(2015, time.January, 1, 0, 0, 0, 0, time.UTC)
         past   = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
         future = now.Add(24 * time.Hour)
 )
@@ skipping 550 matching lines @@
                 return p.tokenToMint, nil
         }
         return &oauth2.Token{AccessToken: "some minted token"}, nil
 }
 
 func (p *fakeTokenProvider) RefreshToken(ctx context.Context, prev, base *oauth2.Token) (*oauth2.Token, error) {
         p.refreshTokenCalled = true
         p.baseTokenInRefresh = base
         if p.transientRefreshErrors != 0 {
                 p.transientRefreshErrors--
-                return nil, errors.WrapTransient(fmt.Errorf("transient error"))
+                return nil, errors.New("transient error", retry.Tag)
         }
         if p.revokedCreds {
                 return nil, internal.ErrBadCredentials
         }
         if p.revokedToken {
                 return nil, internal.ErrBadRefreshToken
         }
         if p.tokenToRefresh != nil {
                 return p.tokenToRefresh, nil
         }
         return &oauth2.Token{AccessToken: "some refreshed token"}, nil
 }