[Sync] Move //sync to //components/sync.

sync/internal_api/public/read_node.h

-// Copyright 2012 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.
-
-#ifndef SYNC_INTERNAL_API_PUBLIC_READ_NODE_H_
-#define SYNC_INTERNAL_API_PUBLIC_READ_NODE_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <string>
-
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "sync/base/sync_export.h"
-#include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/base_node.h"
-
-namespace syncer {
-
-// ReadNode wraps a syncable::Entry to provide the functionality of a
-// read-only BaseNode.
-class SYNC_EXPORT ReadNode : public BaseNode {
- public:
-  // Create an unpopulated ReadNode on the given transaction.  Call some flavor
-  // of Init to populate the ReadNode with a database entry.
-  explicit ReadNode(const BaseTransaction* transaction);
-  ~ReadNode() override;
-
-  // A client must use one (and only one) of the following Init variants to
-  // populate the node.
-
-  // BaseNode implementation.
-  InitByLookupResult InitByIdLookup(int64_t id) override;
-  InitByLookupResult InitByClientTagLookup(ModelType model_type,
-                                           const std::string& tag) override;
-
-  // There is always a root node, so this can't fail.  The root node is
-  // never mutable, so root lookup is only possible on a ReadNode.
-  void InitByRootLookup();
-
-  // Returns the type root node, if it exists.  This is usually created by the
-  // server during first sync.  Eventually, we plan to remove support for it
-  // from the protocol and have the client create the node instead.
-  InitByLookupResult InitTypeRoot(ModelType type);
-
-  // Returns a server-created and unique-server-tagged item.
-  //
-  // This functionality is only useful for bookmarks because only bookmarks
-  // have server-tagged items.  All other server-tagged items are type root
-  // nodes, which should be looked up with InitTypeRoot().
-  InitByLookupResult InitByTagLookupForBookmarks(const std::string& tag);
-
-  // Returns transaction version of the last transaction where this node has
-  // been modified.
-  int64_t GetTransactionVersion() const;
-
-  // Implementation of BaseNode's abstract virtual accessors.
-  const syncable::Entry* GetEntry() const override;
-  const BaseTransaction* GetTransaction() const override;
-
- protected:
-  ReadNode();
-
- private:
-  void* operator new(size_t size);  // Node is meant for stack use only.
-
-  // The underlying syncable object which this class wraps.
-  syncable::Entry* entry_;
-
-  // The sync API transaction that is the parent of this node.
-  const BaseTransaction* transaction_;
-
-  DISALLOW_COPY_AND_ASSIGN(ReadNode);
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_INTERNAL_API_PUBLIC_READ_NODE_H_