Change gae to apache 2 license.

filter/dscache/dscache.go

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
+// 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 dscache
 
 import (
         "bytes"
         "crypto/sha1"
         "encoding/base64"
         "fmt"
         "time"
 
@@ skipping 120 matching lines @@
 
 // HashKey generates just the hashed portion of the MemcacheKey.
 func HashKey(k *datastore.Key) string {
         dgst := sha1.Sum(serialize.ToBytes(k))
         buf := bytes.Buffer{}
         enc := base64.NewEncoder(base64.StdEncoding, &buf)
         _, _ = enc.Write(dgst[:])
         enc.Close()
         return buf.String()[:buf.Len()-Sha1B64Padding]
 }