Remove workaround include_dir

ios/third_party/material_components_ios/BUILD.gn

 # Copyright 2016 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/locales.gni")
 
 config("config") {
   visibility = [ ":material_components_ios" ]
   include_dirs = [
     "src/components/AppBar/src",
@@ skipping 208 matching lines @@
     "src/components/private/ThumbTrack/src/MDCThumbView.m",
     "src/components/private/ThumbTrack/src/MaterialThumbTrack.h",
   ]
   include_dirs = [
     "src/components/ActivityIndicator/src",
     "src/components/AnimationTiming/src",
     "src/components/AppBar/src",
     "src/components/ButtonBar/src",
     "src/components/NavigationBar/src",
     "src/components/OverlayWindow/src",
-
-    # TODO(crbug.com/684379): remove this include once it is not needed anymore.
-    "src/components/Snackbar/src/private",
     "src/components/private/Application/src",
     "src/components/private/Color/src",
     "src/components/private/Icons/src",
     "src/components/private/Icons/icons/ic_arrow_back/src",
     "src/components/private/Icons/icons/ic_check/src",
     "src/components/private/Icons/icons/ic_check_circle/src",
     "src/components/private/Icons/icons/ic_chevron_right/src",
     "src/components/private/Icons/icons/ic_info/src",
     "src/components/private/Icons/icons/ic_radio_button_unchecked/src",
     "src/components/private/Icons/icons/ic_reorder/src",
@@ skipping 92 matching lines @@
     ]
   }
 }
 
 foreach(icon_name, _icon_names) {
   material_component_icon_bundle("material_component_${icon_name}_bundle") {
     visibility = [ ":material_components_ios" ]
     icon_name = "$icon_name"
   }
 }