sync: use progress markers instead of timestamps during GetUpdates

chrome/browser/sync/engine/syncer_thread.cc

Index: chrome/browser/sync/engine/syncer_thread.cc
diff --git a/chrome/browser/sync/engine/syncer_thread.cc b/chrome/browser/sync/engine/syncer_thread.cc
index 3c0cd066be172084230bf1c92e6748ba5edf8a2f..7d9fa170ebbafc26542c45765cf11c3714aee80c 100644
--- a/chrome/browser/sync/engine/syncer_thread.cc
+++ b/chrome/browser/sync/engine/syncer_thread.cc
@@ -472,8 +472,8 @@ SyncerThread::WaitInterval SyncerThread::CalculatePollingWaitTime(
   // Determine if the syncer has unfinished work to do.
   SyncSessionSnapshot* snapshot = session_context_->previous_session_snapshot();
   const bool syncer_has_work_to_do = snapshot &&
-      (snapshot->num_server_changes_remaining > snapshot->max_local_timestamp ||
-          snapshot->unsynced_count > 0);
+      (snapshot->num_server_changes_remaining > 0 ||
+       snapshot->unsynced_count > 0);
   VLOG(1) << "syncer_has_work_to_do is " << syncer_has_work_to_do;
 
   // First calculate the expected wait time, figuring in any backoff because of