Address some TODO(GYP)s in the GN build.

ui/resources/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("//tools/grit/grit_rule.gni")
 import("//tools/grit/repack.gni")
 
 # GYP version: ui/resources/ui_resources.gyp:ui_resources
 group("resources") {
   public_deps = [
@@ skipping 13 matching lines @@
     "ui_resources_200_percent.pak",
     "ui_resources_300_percent.pak",
   ]
 }
 
 grit("ui_unscaled_resources_grd") {
   source = "ui_unscaled_resources.grd"
   use_qualified_include = true
   outputs = [
     "grit/ui_unscaled_resources.h",
+
+    # TODO(GYP_GONE) when GYP is gone, this line should be deleted, and the grit
+    # file updated to no longer list this as an output. We use resource bundles
+    # rather than .rc files, but the GYP build still expects this file to
+    # exist.
     "ui_unscaled_resources.rc",
   ]
 }
 
 grit("webui_resources_grd") {
   source = "../webui/resources/webui_resources.grd"
   outputs = [
     "grit/webui_resources.h",
     "grit/webui_resources_map.cc",
     "grit/webui_resources_map.h",
@@ skipping 175 matching lines @@
     "$root_gen_dir/ui/strings/app_locale_settings_en-US.pak",
     "$root_gen_dir/ui/strings/ui_strings_en-US.pak",
   ]
 
   output = "$root_out_dir/ui/en.lproj/locale.pak"
 
   deps = [
     "//ui/strings",
   ]
 }