[Sync] Signal UIModelWorker to abort on sync shutdown.

components/sync/engine/model_safe_worker.cc

Index: components/sync/engine/model_safe_worker.cc
diff --git a/components/sync/engine/model_safe_worker.cc b/components/sync/engine/model_safe_worker.cc
index 530f206599673cf1b91239e5d40aeff463b0406c..f61cda0c1c836402dd44ddba82164eca11d8b916 100644
--- a/components/sync/engine/model_safe_worker.cc
+++ b/components/sync/engine/model_safe_worker.cc
@@ -79,14 +79,14 @@ void ModelSafeWorker::RequestStop() {
   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