Add Store+Sync to reading list.

components/browser_sync/profile_sync_components_factory_impl.cc

Index: components/browser_sync/profile_sync_components_factory_impl.cc
diff --git a/components/browser_sync/profile_sync_components_factory_impl.cc b/components/browser_sync/profile_sync_components_factory_impl.cc
index f71096c80b08db9f02f09e32904a0a1aea4f7899..c4332e02bdc969cd0fa5b05a11bd7e5b61822f33 100644
--- a/components/browser_sync/profile_sync_components_factory_impl.cc
+++ b/components/browser_sync/profile_sync_components_factory_impl.cc
@@ -274,6 +274,14 @@ void ProfileSyncComponentsFactoryImpl::RegisterCommonDataTypes(
         base::MakeUnique<UIDataTypeController>(syncer::ARTICLES, error_callback,
                                                sync_client_));
   }
+  // Reading list sync is disabled by default.  Register only if explicitly
+  // enabled.
+  if (enabled_types.Has(syncer::READING_LIST)) {
+    sync_service->RegisterDataTypeController(
+        base::MakeUnique<ModelTypeController>(
+            syncer::READING_LIST, error_callback, sync_client_,
+            base::ThreadTaskRunnerHandle::Get()));
+  }
 }
 
 DataTypeManager* ProfileSyncComponentsFactoryImpl::CreateDataTypeManager(