Make it clear what last_sync_timestamp actually tracks. Update

chrome/browser/sync/sessions/sync_session.cc

 // Copyright (c) 2009 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.
 
 #include "chrome/browser/sync/sessions/sync_session.h"
 #include "chrome/browser/sync/syncable/directory_manager.h"
 
 namespace browser_sync {
 namespace sessions {
 
@@ skipping 35 matching lines @@
   sync_pb::GetUpdatesCallerInfo::GetUpdatesSource old_source = source_;
   set_source(sync_pb::GetUpdatesCallerInfo::SYNC_CYCLE_CONTINUATION);
   return old_source;
 }
 
 bool SyncSession::HasMoreToSync() const {
   const StatusController* status = status_controller_.get();
   return ((status->commit_ids().size() < status->unsynced_handles().size()) &&
       status->syncer_status().num_successful_commits > 0) ||
       status->conflict_sets_built() ||
-      status->conflicts_resolved() ||
+      status->conflicts_resolved();
       // Or, we have conflicting updates, but we're making progress on
       // resolving them...
-      !status->got_zero_updates() ||
-      status->got_new_timestamp();
-}
+  }
 
 }  // namespace sessions
 }  // namespace browser_sync