[Sync] Move //components/sync to the syncer namespace.

components/sync/core/data_batch_impl_unittest.cc

 // 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.
 
 #include "components/sync/core/data_batch_impl.h"
 
 #include "base/memory/ptr_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace syncer_v2 {
+namespace syncer {
 
 TEST(DataBatchImplTest, PutAndNextWithReuse) {
   EntityData* entity1 = new EntityData();
   EntityData* entity2 = new EntityData();
 
   DataBatchImpl batch;
   EXPECT_FALSE(batch.HasNext());
 
   batch.Put("one", base::WrapUnique(entity1));
   EXPECT_TRUE(batch.HasNext());
@@ skipping 60 matching lines @@
   EXPECT_TRUE(batch.HasNext());
   EXPECT_EQ("same", pair1.first);
   EXPECT_EQ(entity1, pair1.second.get());
 
   const KeyAndData& pair2 = batch.Next();
   EXPECT_FALSE(batch.HasNext());
   EXPECT_EQ("same", pair2.first);
   EXPECT_EQ(entity2, pair2.second.get());
 }
 
-}  // namespace syncer_v2
+}  // namespace syncer