[Sync] Replace typedef with using.

components/sync/base/attachment_id_proto_unittest.cc

 // Copyright 2014 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.
 
 #include "components/sync/base/attachment_id_proto.h"
 
 #include "base/strings/string_util.h"
 #include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace syncer {
 
-typedef testing::Test AttachmentIdProtoTest;
+using AttachmentIdProtoTest = testing::Test;
 
 // Verify that that we generate a proto with a properly formatted unique_id
 // field.
 TEST(AttachmentIdProtoTest, UniqueIdFormat) {
   sync_pb::AttachmentIdProto id_proto = CreateAttachmentIdProto(0, 0);
   ASSERT_TRUE(id_proto.has_unique_id());
   // gtest's regular expression support is pretty poor so we cannot test as
   // closely as we would like.
   EXPECT_THAT(id_proto.unique_id(),
               testing::MatchesRegex(
@@ skipping 16 matching lines @@
   sync_pb::AttachmentMetadata metadata = CreateAttachmentMetadata(ids);
   ASSERT_EQ(3, metadata.record_size());
   for (int i = 0; i < metadata.record_size(); ++i) {
     EXPECT_EQ(ids.Get(i).SerializeAsString(),
               metadata.record(i).id().SerializeAsString());
     EXPECT_TRUE(metadata.record(i).is_on_server());
   }
 }
 
 }  // namespace syncer