sync: Consistently refcount ModelSafeWorkers

sync/sessions/sync_session_context.h

Index: sync/sessions/sync_session_context.h
diff --git a/sync/sessions/sync_session_context.h b/sync/sessions/sync_session_context.h
index 5995ab151dbcbba209872310ce532fcfa3030da7..2e2433e41defcc82d737e5c3a6981e60d34ff951 100644
--- a/sync/sessions/sync_session_context.h
+++ b/sync/sessions/sync_session_context.h
@@ -47,16 +47,17 @@ class TestScopedSessionEventListener;
 
 class SYNC_EXPORT_PRIVATE SyncSessionContext {
  public:
-  SyncSessionContext(ServerConnectionManager* connection_manager,
-                     syncable::Directory* directory,
-                     const std::vector<ModelSafeWorker*>& workers,
-                     ExtensionsActivity* extensions_activity,
-                     const std::vector<SyncEngineEventListener*>& listeners,
-                     DebugInfoGetter* debug_info_getter,
-                     TrafficRecorder* traffic_recorder,
-                     bool keystore_encryption_enabled,
-                     bool client_enabled_pre_commit_update_avoidance,
-                     const std::string& invalidator_client_id);
+  SyncSessionContext(
+      ServerConnectionManager* connection_manager,
+      syncable::Directory* directory,
+      const std::vector<scoped_refptr<ModelSafeWorker> >& workers,
+      ExtensionsActivity* extensions_activity,
+      const std::vector<SyncEngineEventListener*>& listeners,
+      DebugInfoGetter* debug_info_getter,
+      TrafficRecorder* traffic_recorder,
+      bool keystore_encryption_enabled,
+      bool client_enabled_pre_commit_update_avoidance,
+      const std::string& invalidator_client_id);
 
   ~SyncSessionContext();