[Sync] Fix sync scheduler/session logic determining successful commands.

sync/engine/sync_scheduler.cc

 // Copyright (c) 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.
 
 #include "sync/engine/sync_scheduler.h"
 
 #include <algorithm>
 #include <cstring>
 
 #include "base/bind.h"
@@ skipping 863 matching lines @@
   ScheduleNextSync(job);
 }
 
 void SyncScheduler::ScheduleNextSync(const SyncSessionJob& old_job) {
   DCHECK_EQ(MessageLoop::current(), sync_loop_);
   DCHECK(!old_job.session->HasMoreToSync());
 
   AdjustPolling(&old_job);
 
   if (old_job.session->Succeeded()) {
-    // Success implies backoff relief.  Note that if this was a
-    // "one-off" job (i.e. purpose ==
-    // SyncSessionJob::{CLEAR_USER_DATA,CLEANUP_DISABLED_TYPES}), if
-    // there was work to do before it ran this wont have changed, as
-    // jobs like this don't run a full sync cycle.  So we don't need
-    // special code here.
-    wait_interval_.reset();
+    // Only reset backoff if we actually reached the server.
+    if (old_job.session->SuccessfullyReachedServer())
+      wait_interval_.reset();
     SDVLOG(2) << "Job succeeded so not scheduling more jobs";
     return;
   }
 
   if (old_job.purpose == SyncSessionJob::POLL) {
     return; // We don't retry POLL jobs.
   }
 
   // TODO(rlarocque): There's no reason why we should blindly backoff and retry
   // if we don't succeed.  Some types of errors are not likely to disappear on
@@ skipping 294 matching lines @@
 
 #undef SDVLOG_LOC
 
 #undef SDVLOG
 
 #undef SLOG
 
 #undef ENUM_CASE
 
 }  // browser_sync