Move enable_mdns build flag to net.

net/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
@@ skipping 28 matching lines @@
 
 use_v8_in_net = !is_ios
 enable_built_in_dns = !is_ios
 
 buildflag_header("features") {
   header = "net_features.h"
   flags = [
     "POSIX_AVOID_MMAP=$posix_avoid_mmap",
     "DISABLE_FILE_SUPPORT=$disable_file_support",
     "DISABLE_FTP_SUPPORT=$disable_ftp_support",
+    "ENABLE_MDNS=$enable_mdns",
     "ENABLE_WEBSOCKETS=$enable_websockets",
   ]
 }
 
 config("net_internal_config") {
   defines = [
     "DLOPEN_KERBEROS",
     "NET_IMPLEMENTATION",
   ]
 
@@ skipping 1982 matching lines @@
     "http/http_security_headers_hpkp_report_only_fuzzer.cc",
   ]
   deps = [
     ":net_fuzzer_test_support",
     "//base",
     "//net",
     "//url",
   ]
   dict = "data/fuzzer_dictionaries/net_http_security_headers_fuzzer.dict"
 }