[USS] Move GetAllNodes from backend to controller

components/sync/core_impl/test/fake_sync_manager.cc

Index: components/sync/core_impl/test/fake_sync_manager.cc
diff --git a/components/sync/core_impl/test/fake_sync_manager.cc b/components/sync/core_impl/test/fake_sync_manager.cc
index a102889a07ea0953b6ff3f85ea4813e6fa2e4eb3..8889689f4dde1ba49ec3b7f40c46985641fe2998 100644
--- a/components/sync/core_impl/test/fake_sync_manager.cc
+++ b/components/sync/core_impl/test/fake_sync_manager.cc
@@ -226,11 +226,6 @@ FakeSyncManager::GetBufferedProtocolEvents() {
   return ScopedVector<syncer::ProtocolEvent>();
 }
 
-std::unique_ptr<base::ListValue> FakeSyncManager::GetAllNodesForType(
-    syncer::ModelType type) {
-  return std::unique_ptr<base::ListValue>(new base::ListValue());
-}
-
 void FakeSyncManager::RefreshTypes(ModelTypeSet types) {
   last_refresh_request_types_ = types;
 }