Implement new SyncAPI and convert Preferences to it.

chrome/browser/sync/api/syncable_service.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.
+
+#ifndef CHROME_BROWSER_SYNC_API_SYNCABLE_SERVICE_H_
+#define CHROME_BROWSER_SYNC_API_SYNCABLE_SERVICE_H_
+#pragma once
+
+#include <vector>
+
+#include "chrome/browser/sync/syncable/model_type.h"
+#include "chrome/browser/sync/api/sync_event_processor.h"
+
+class SyncData;
+
+typedef std::vector<SyncData> SyncDataList;
+
+class SyncableService : public SyncEventProcessor {
+ public:
+  SyncableService();
+  virtual ~SyncableService();
+
+  // Informs the service to begin syncing the specified synced datatype |type|.
+  // The service should then merge |initial_sync_data| into it's local data,
+  // calling |sync_processor|'s ProcessSyncEvents as necessary to reconcile the
+  // two. After this, the SyncableService's local data should match the server
+  // data, and the service should be ready to receive and process any further
+  // SyncEvent's as they occur.
+  virtual bool MergeDataAndStartSyncing(
+      syncable::ModelType type,

[akalin, 2011/05/19 00:58:45]

I'm not a fan of needing to reference the syncable namespace here.  I notice we
have a SyncDataType typedef in sync_data.h.  Perhaps have a sync_data_type.h
that only has 'typedef syncable::ModelType SyncDataType' and use that
everywhere?

[Nicolas Zea, 2011/05/19 21:17:45]

I don't think it's anything we can really avoid. The syncableservice's should be
using model_type's util methods anyways. And it reinforces that this is
something coming from the syncer.

+      SyncEventProcessor* sync_processor,
+      const SyncDataList& initial_sync_data) = 0;

[akalin, 2011/05/19 00:58:45]

maybe move initial-sync_data to before the sync_processor, since that follows
the order of the name (merge, then start syncing)

[Nicolas Zea, 2011/05/19 21:17:45]

Done.

+
+  // Stop syncing the specified type and reset state.
+  virtual void StopSyncing(syncable::ModelType type) = 0;
+
+  // Fills a list of SyncData from the local data. This should create an up
+  // to date representation of the SyncableService's view of that datatype, and
+  // should match/be a subset of the server's view of that datatype.
+  virtual bool GetAllSyncData(syncable::ModelType type,
+                              SyncDataList* current_data) = 0;
+
+  // SyncEventProcessor interface.
+  // Process a list of new SyncEvents and update the local data as necessary.
+  virtual void ProcessSyncEvents(const SyncEventList& event_list) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SyncableService);
+};
+
+#endif  // CHROME_BROWSER_SYNC_API_SYNCABLE_SERVICE_H_