sync: Per-type update application

sync/sessions/sync_session.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.
 
 // A class representing an attempt to synchronize the local syncable data
 // store with a sync server. A SyncSession instance is passed as a stateful
-// bundle to and from various SyncerCommands with the goal of converging the
-// client view of data with that of the server. The commands twiddle with
-// session status in response to events and hiccups along the way, set and
-// query session progress with regards to conflict resolution and applying
-// server updates, and access the SyncSessionContext for the current session
-// via SyncSession instances.
+// bundle throughout the sync cycle.  The SyncSession is not reused across
+// sync cycles; each cycle starts with a new one.
 
 #ifndef SYNC_SESSIONS_SYNC_SESSION_H_
 #define SYNC_SESSIONS_SYNC_SESSION_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 105 matching lines @@
   // Our controller for various status and error counters.
   scoped_ptr<StatusController> status_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSession);
 };
 
 }  // namespace sessions
 }  // namespace syncer
 
 #endif  // SYNC_SESSIONS_SYNC_SESSION_H_