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

components/sync/api/metadata_batch.h

Index: components/sync/api/metadata_batch.h
diff --git a/components/sync/api/metadata_batch.h b/components/sync/api/metadata_batch.h
index 18f772d254fa10d2e4913438c9f1690a982ee0b0..846befe6ec97076bc1ec2465090dbb5fdcf8ff3d 100644
--- a/components/sync/api/metadata_batch.h
+++ b/components/sync/api/metadata_batch.h
@@ -11,7 +11,7 @@
 #include "components/sync/protocol/data_type_state.pb.h"
 #include "components/sync/protocol/entity_metadata.pb.h"
 
-namespace syncer_v2 {
+namespace syncer {
 
 // Map of storage keys to EntityMetadata proto.
 typedef std::map<std::string, sync_pb::EntityMetadata> EntityMetadataMap;
@@ -42,6 +42,6 @@ class MetadataBatch {
   sync_pb::DataTypeState state_;
 };
 
-}  // namespace syncer_v2
+}  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_API_METADATA_BATCH_H_