Make enable_service_discovery a chrome/ feature.

chrome/app/BUILD.gn

 # Copyright 2014 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/config/ui.gni")
+import("//chrome/common/features.gni")
 import("//services/shell/public/service_manifest.gni")
 import("//tools/grit/grit_rule.gni")
 
 # This target is for dependency tracking for the command ID header.
 source_set("command_ids") {
   sources = [
     "chrome_command_ids.h",
   ]
 }
 
@@ skipping 56 matching lines @@
     "java/res/values-vi/generated_resources.xml",
     "java/res/values-zh-rCN/generated_resources.xml",
     "java/res/values-zh-rTW/generated_resources.xml",
     "java/res/values/generated_resources.xml",
   ]
 }
 
 grit("generated_resources") {
   source = "generated_resources.grd"
   use_qualified_include = true
+  defines = chrome_grit_defines
   output_dir = "$root_gen_dir/chrome"
   outputs = [
     "grit/generated_resources.h",
     "generated_resources_am.pak",
     "generated_resources_ar.pak",
     "generated_resources_bg.pak",
     "generated_resources_bn.pak",
     "generated_resources_ca.pak",
     "generated_resources_cs.pak",
     "generated_resources_da.pak",
@@ skipping 298 matching lines @@
 
   group("service_manifests") {
     data_deps = [
       ":chrome_content_browser_manifest",
       ":chrome_content_gpu_manifest",
       ":chrome_content_renderer_manifest",
       ":chrome_content_utility_manifest",
     ]
   }
 }