message: Added support for RefMerge and RefSwitch to grappler
diff: @@ -47,7 +47,7 @@ bool IsIdentity(const NodeDef& node) {
  bool IsMerge(const NodeDef& node) {
  const auto op = node.op();
  - return op == "Merge";
  + return op == "Merge" || op == "RefMerge";
  }
  bool IsNoOp(const NodeDef& node) {
  @@ -91,7 +91,7 @@ bool IsStopGradient(const NodeDef& node) {
  bool IsSwitch(const NodeDef& node) {
  const auto& op = node.op();
  - return op == "Switch";
  + return op == "Switch" || op == "RefSwitch";
  }
  bool IsTranspose(const NodeDef& node) {
  