Merge pull request #24542 from ananda1066/address_name

Added ADDRESS_NAME arg to resolver.h.

src/core/ext/filters/client_channel/resolver.h

@@ -32,6 +32,9 @@
 
 extern grpc_core::DebugOnlyTraceFlag grpc_trace_resolver_refcount;
 
+// Name associated with individual address, if available.
+#define GRPC_ARG_ADDRESS_NAME "grpc.address_name";
+
 namespace grpc_core {
 
 /// Interface for name resolution.