message: Avoid using the Graph owned FunctionLibraryDefinition in Dataset::FromGraph
  This is part of a series of change intended to decouple the FunctionLibraryDefinition
  from the Graph entirely.
diff: @@ -68,10 +68,10 @@ Status Dataset::FromGraph(Params params, const GraphDef& graph_def,
  auto device_mgr = absl::make_unique<StaticDeviceMgr>(DeviceFactory::NewDevice(
  "CPU", params.session_options, "/job:localhost/replica:0/task:0"));
  Device* device = device_mgr->ListDevices()[0];
  - // Clone the `FunctionLibraryDefinition` to extend its lifetime extends beyond
  + // Create a copy of the `FunctionLibraryDefinition` to extend lifetime beyond
  // the lifetime of `graph`.
  - auto flib_def =
  - absl::make_unique<FunctionLibraryDefinition>(graph.flib_def());
  + auto flib_def = absl::make_unique<FunctionLibraryDefinition>(
  + OpRegistry::Global(), graph_def.library());
  auto pflr = absl::make_unique<ProcessFunctionLibraryRuntime>(
  device_mgr.get(), Env::Default(), /*config=*/nullptr,
  TF_GRAPH_DEF_VERSION, flib_def.get(), OptimizerOptions{},
  