vendor: update dependencies to latest

vendor/golang.org/x/oauth2/google/appengine.go

@@ -5,85 +5,34 @@
 package google
 
 import (
-	"sort"
-	"strings"
-	"sync"
+	"context"
 	"time"
 
-	"golang.org/x/net/context"
 	"golang.org/x/oauth2"
 )
 
-// appengineFlex is set at init time by appengineflex_hook.go. If true, we are on App Engine Flex.
-var appengineFlex bool
-
-// Set at init time by appengine_hook.go. If nil, we're not on App Engine.
+// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
 var appengineTokenFunc func(c context.Context, scopes ...string) (token string, expiry time.Time, err error)
 
-// Set at init time by appengine_hook.go. If nil, we're not on App Engine.
+// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
 var appengineAppIDFunc func(c context.Context) string
 
-// AppEngineTokenSource returns a token source that fetches tokens
-// issued to the current App Engine application's service account.
-// If you are implementing a 3-legged OAuth 2.0 flow on App Engine
-// that involves user accounts, see oauth2.Config instead.
+// AppEngineTokenSource returns a token source that fetches tokens from either
+// the current application's service account or from the metadata server,
+// depending on the App Engine environment. See below for environment-specific
+// details. If you are implementing a 3-legged OAuth 2.0 flow on App Engine that
+// involves user accounts, see oauth2.Config instead.
 //
-// The provided context must have come from appengine.NewContext.
+// First generation App Engine runtimes (<= Go 1.9):
+// AppEngineTokenSource returns a token source that fetches tokens issued to the
+// current App Engine application's service account. The provided context must have
+// come from appengine.NewContext.
+//
+// Second generation App Engine runtimes (>= Go 1.11) and App Engine flexible:
+// AppEngineTokenSource is DEPRECATED on second generation runtimes and on the
+// flexible environment. It delegates to ComputeTokenSource, and the provided
+// context and scopes are not used. Please use DefaultTokenSource (or ComputeTokenSource,
+// which DefaultTokenSource will use in this case) instead.
 func AppEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
-	if appengineTokenFunc == nil {
-		panic("google: AppEngineTokenSource can only be used on App Engine.")
-	}
-	scopes := append([]string{}, scope...)
-	sort.Strings(scopes)
-	return &appEngineTokenSource{
-		ctx:    ctx,
-		scopes: scopes,
-		key:    strings.Join(scopes, " "),
-	}
-}
-
-// aeTokens helps the fetched tokens to be reused until their expiration.
-var (
-	aeTokensMu sync.Mutex
-	aeTokens   = make(map[string]*tokenLock) // key is space-separated scopes
-)
-
-type tokenLock struct {
-	mu sync.Mutex // guards t; held while fetching or updating t
-	t  *oauth2.Token
-}
-
-type appEngineTokenSource struct {
-	ctx    context.Context
-	scopes []string
-	key    string // to aeTokens map; space-separated scopes
-}
-
-func (ts *appEngineTokenSource) Token() (*oauth2.Token, error) {
-	if appengineTokenFunc == nil {
-		panic("google: AppEngineTokenSource can only be used on App Engine.")
-	}
-
-	aeTokensMu.Lock()
-	tok, ok := aeTokens[ts.key]
-	if !ok {
-		tok = &tokenLock{}
-		aeTokens[ts.key] = tok
-	}
-	aeTokensMu.Unlock()
-
-	tok.mu.Lock()
-	defer tok.mu.Unlock()
-	if tok.t.Valid() {
-		return tok.t, nil
-	}
-	access, exp, err := appengineTokenFunc(ts.ctx, ts.scopes...)
-	if err != nil {
-		return nil, err
-	}
-	tok.t = &oauth2.Token{
-		AccessToken: access,
-		Expiry:      exp,
-	}
-	return tok.t, nil
+	return appEngineTokenSource(ctx, scope...)
 }