[Sync] Sync client should to exponential backoff when receive partial failure

components/sync/engine_impl/all_status.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 "components/sync/engine_impl/all_status.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "components/sync/engine_impl/net/server_connection_manager.h"
@@ skipping 82 matching lines @@
 void AllStatus::OnRetryTimeChanged(base::Time retry_time) {
   ScopedStatusLock lock(this);
   status_.retry_time = retry_time;
 }
 
 void AllStatus::OnThrottledTypesChanged(ModelTypeSet throttled_types) {
   ScopedStatusLock lock(this);
   status_.throttled_types = throttled_types;
 }
 
+void AllStatus::OnBackedOffTypesChanged(ModelTypeSet backed_off_types) {
+  ScopedStatusLock lock(this);
+  status_.backed_off_types = backed_off_types;
+}
+
 void AllStatus::OnMigrationRequested(ModelTypeSet) {}
 
 void AllStatus::OnProtocolEvent(const ProtocolEvent&) {}
 
 SyncStatus AllStatus::status() const {
   base::AutoLock lock(mutex_);
   return status_;
 }
 
 void AllStatus::SetNotificationsEnabled(bool notifications_enabled) {
@@ skipping 70 matching lines @@
 ScopedStatusLock::ScopedStatusLock(AllStatus* allstatus)
     : allstatus_(allstatus) {
   allstatus->mutex_.Acquire();
 }
 
 ScopedStatusLock::~ScopedStatusLock() {
   allstatus_->mutex_.Release();
 }
 
 }  // namespace syncer