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

sync/api/sync_change.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_API_SYNC_CHANGE_H_
-#define SYNC_API_SYNC_CHANGE_H_
-
-#include <iosfwd>
-#include <string>
-#include <vector>
-
-#include "base/location.h"
-#include "sync/api/sync_data.h"
-#include "sync/base/sync_export.h"
-
-namespace syncer {
-
-// A SyncChange object reflects a change to a piece of synced data. The change
-// can be either a delete, add, or an update. All data relevant to the change
-// is encapsulated within the SyncChange, which, once created, is immutable.
-// Note: it is safe and cheap to pass these by value or make copies, as they do
-// not create deep copies of their internal data.
-class SYNC_EXPORT SyncChange {
- public:
-  enum SyncChangeType {
-    ACTION_INVALID,
-    ACTION_ADD,
-    ACTION_UPDATE,
-    ACTION_DELETE,
-  };
-
-  // Default constructor creates an invalid change.
-  SyncChange();
-  // Create a new change with the specified sync data.
-  SyncChange(
-      const tracked_objects::Location& from_here,
-      SyncChangeType change_type,
-      const SyncData& sync_data);
-  ~SyncChange();
-
-  // Copy constructor and assignment operator welcome.
-
-  // Whether this change is valid. This must be true before attempting to access
-  // the data.
-  // Deletes: Requires valid tag when going to the syncer. Requires valid
-  //          specifics when coming from the syncer.
-  // Adds, Updates: Require valid tag and specifics when going to the syncer.
-  //                Require only valid specifics when coming from the syncer.
-  bool IsValid() const;
-
-  // Getters.
-  SyncChangeType change_type() const;
-  SyncData sync_data() const;
-  tracked_objects::Location location() const;
-
-  // Returns a string representation of |change_type|.
-  static std::string ChangeTypeToString(SyncChangeType change_type);
-
-  // Returns a string representation of the entire object. Used for gmock
-  // printing method, PrintTo.
-  std::string ToString() const;
-
- private:
-  tracked_objects::Location location_;
-
-  SyncChangeType change_type_;
-
-  // An immutable container for the data of this SyncChange. Whenever
-  // SyncChanges are copied, they copy references to this data.
-  SyncData sync_data_;
-};
-
-// gmock printer helper.
-SYNC_EXPORT void PrintTo(const SyncChange& sync_change, std::ostream* os);
-
-}  // namespace syncer
-
-#endif  // SYNC_API_SYNC_CHANGE_H_