[Sync] Signal UIModelWorker to abort on sync shutdown.

components/sync/engine/model_safe_worker.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/model_safe_worker.h"
 
 #include "base/json/json_writer.h"
 #include "base/values.h"
 
 namespace syncer {
@@ skipping 61 matching lines @@
 ModelSafeWorker::ModelSafeWorker() {}
 ModelSafeWorker::~ModelSafeWorker() {}
 
 void ModelSafeWorker::RequestStop() {
   // Set stop flag. This prevents any *further* tasks from being posted to
   // worker threads (see DoWorkAndWaitUntilDone below), but note that one may
   // already be posted.
   stopped_.Set();
 }
 
+bool ModelSafeWorker::IsStopped() {

[maxbogue, 2016/11/18 18:26:51]

IsStopped() is still below DoWorkAndWaitUntilDone in the header so you can
probably revert this file.

[fdoray, 2016/11/21 16:57:56]

Done.

+  return stopped_.IsSet();
+}
+
 SyncerError ModelSafeWorker::DoWorkAndWaitUntilDone(const WorkCallback& work) {
   if (stopped_.IsSet())
     return CANNOT_DO_WORK;
   return DoWorkAndWaitUntilDoneImpl(work);
 }
 
-bool ModelSafeWorker::IsStopped() {
-  return stopped_.IsSet();
-}
-
 }  // namespace syncer