[Sync] Move ChangeRecord into its own file (change_record.{h,cc})

chrome/browser/sync/internal_api/change_reorder_buffer.h

 // Copyright (c) 2011 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.
 //
 // Defines ChangeReorderBuffer, which can be used to sort a list of item
 // actions to achieve the ordering constraint required by the SyncObserver
 // interface of the SyncAPI.
 
 #ifndef CHROME_BROWSER_SYNC_INTERNAL_API_CHANGE_REORDER_BUFFER_H_
 #define CHROME_BROWSER_SYNC_INTERNAL_API_CHANGE_REORDER_BUFFER_H_
 #pragma once
 
 #include <map>
 #include <vector>
 
 #include "base/memory/linked_ptr.h"
 #include "chrome/browser/sync/internal_api/base_transaction.h"
-#include "chrome/browser/sync/internal_api/sync_manager.h"
+#include "chrome/browser/sync/internal_api/change_record.h"
 #include "chrome/browser/sync/protocol/sync.pb.h"
 
 namespace sync_api {
 
 // ChangeReorderBuffer is a utility type which accepts an unordered set
-// of changes (via its Push methods), and yields a vector of ChangeRecords
+// of changes (via its Push methods), and yields an ImmutableChangeRecordList
 // (via the GetAllChangesInTreeOrder method) that are in the order that
 // the SyncObserver expects them to be. A buffer is initially empty.
 //
 // The ordering produced by ChangeReorderBuffer is as follows:
 //  (a) All Deleted items appear first.
 //  (b) For Updated and/or Added items, parents appear before their children.
 //  (c) When there are changes to the sibling order (this means Added items,
 //      or Updated items with the |position_changed| parameter set to true),
 //      all siblings under a parent will appear in the output, even if they
 //      are not explicitly pushed.  The sibling order will be preserved in
 //      the output list -- items will appear before their sibling-order
 //      successors.
 //  (d) When there are no changes to the sibling order under a parent node,
 //      the sibling order is not necessarily preserved in the output for
 //      its children.
 class ChangeReorderBuffer {
  public:
-  typedef SyncManager::ChangeRecord ChangeRecord;
-  typedef SyncManager::ExtraPasswordChangeRecordData ExtraChangeRecordData;
-
   ChangeReorderBuffer();
   ~ChangeReorderBuffer();
 
   // Insert an item, identified by the metahandle |id|, into the reorder
   // buffer. This item will appear in the output list as an ACTION_ADD
   // ChangeRecord.
   void PushAddedItem(int64 id) {
     operations_[id] = OP_ADD;
   }
 
   // Insert an item, identified by the metahandle |id|, into the reorder
   // buffer. This item will appear in the output list as an ACTION_DELETE
   // ChangeRecord.
   void PushDeletedItem(int64 id) {
     operations_[id] = OP_DELETE;
   }
 
   // Insert an item, identified by the metahandle |id|, into the reorder
   // buffer. This item will appear in the output list as an ACTION_UPDATE
   // ChangeRecord. Also, if |position_changed| is true, all siblings of this
   // item will appear in the output list as well; if it wasn't explicitly
   // pushed, the siblings will have an ACTION_UPDATE ChangeRecord.
   void PushUpdatedItem(int64 id, bool position_changed) {
     operations_[id] = position_changed ? OP_UPDATE_POSITION_AND_PROPERTIES :
                                          OP_UPDATE_PROPERTIES_ONLY;
   }
 
-  void SetExtraDataForId(int64 id, ExtraChangeRecordData* extra) {
-    extra_data_[id] = make_linked_ptr<ExtraChangeRecordData>(extra);
+  void SetExtraDataForId(int64 id, ExtraPasswordChangeRecordData* extra) {
+    extra_data_[id] = make_linked_ptr<ExtraPasswordChangeRecordData>(extra);
   }
 
   void SetSpecificsForId(int64 id, const sync_pb::EntitySpecifics& specifics) {
     specifics_[id] = specifics;
   }
 
   // Reset the buffer, forgetting any pushed items, so that it can be used
   // again to reorder a new set of changes.
   void Clear() {
     operations_.clear();
   }
 
   bool IsEmpty() const {
     return operations_.empty();
   }
 
   // Output a reordered list of changes to |changelist| using the items that
   // were pushed into the reorder buffer. |sync_trans| is used to determine the
   // ordering.
-  void GetAllChangesInTreeOrder(const BaseTransaction* sync_trans,
-                                std::vector<ChangeRecord>* changelist);
+  ImmutableChangeRecordList
+      GetAllChangesInTreeOrder(const BaseTransaction* sync_trans);
 
  private:
   class Traversal;
   enum Operation {
     OP_ADD,                             // AddedItem.
     OP_DELETE,                          // DeletedItem.
     OP_UPDATE_PROPERTIES_ONLY,          // UpdatedItem with position_changed=0.
     OP_UPDATE_POSITION_AND_PROPERTIES,  // UpdatedItem with position_changed=1.
   };
   typedef std::map<int64, Operation> OperationMap;
   typedef std::map<int64, sync_pb::EntitySpecifics> SpecificsMap;
-  typedef std::map<int64, linked_ptr<ExtraChangeRecordData> > ExtraDataMap;
+  typedef std::map<int64, linked_ptr<ExtraPasswordChangeRecordData> >
+      ExtraDataMap;
 
   // Stores the items that have been pushed into the buffer, and the type of
   // operation that was associated with them.
   OperationMap operations_;
 
   // Stores entity-specific ChangeRecord data per-ID.
   SpecificsMap specifics_;
 
   // Stores type-specific extra data per-ID.
   ExtraDataMap extra_data_;
 
   DISALLOW_COPY_AND_ASSIGN(ChangeReorderBuffer);
 };
 
 }  // namespace sync_api
 
 #endif  // CHROME_BROWSER_SYNC_INTERNAL_API_CHANGE_REORDER_BUFFER_H_