[CRD iOS] Branching internal and external implementations

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 145 matching lines @@
     "src/components/Snackbar/src/MDCSnackbarMessageView.h",
     "src/components/Snackbar/src/MDCSnackbarMessageView.m",
     "src/components/Snackbar/src/MaterialSnackbar.h",
     "src/components/Snackbar/src/private/MDCSnackbarMessageInternal.h",
     "src/components/Snackbar/src/private/MDCSnackbarMessageViewInternal.h",
     "src/components/Snackbar/src/private/MDCSnackbarOverlayView.h",
     "src/components/Snackbar/src/private/MDCSnackbarOverlayView.m",
     "src/components/Typography/src/MDCTypography.h",
     "src/components/Typography/src/MDCTypography.m",
     "src/components/Typography/src/MaterialTypography.h",
+    "src/components/Typography/src/private/UIFont+MaterialTypographyPrivate.h",
+    "src/components/Typography/src/private/UIFont+MaterialTypographyPrivate.m",
     "src/components/private/Application/src/MaterialApplication.h",
     "src/components/private/Application/src/UIApplication+AppExtensions.h",
     "src/components/private/Application/src/UIApplication+AppExtensions.m",
     "src/components/private/Icons/icons/ic_arrow_back/src/MaterialIcons+ic_arrow_back.h",
     "src/components/private/Icons/icons/ic_arrow_back/src/MaterialIcons+ic_arrow_back.m",
     "src/components/private/Icons/icons/ic_check/src/MaterialIcons+ic_check.h",
     "src/components/private/Icons/icons/ic_check/src/MaterialIcons+ic_check.m",
     "src/components/private/Icons/icons/ic_check_circle/src/MaterialIcons+ic_check_circle.h",
     "src/components/private/Icons/icons/ic_check_circle/src/MaterialIcons+ic_check_circle.m",
     "src/components/private/Icons/icons/ic_chevron_right/src/MaterialIcons+ic_chevron_right.h",
@@ skipping 186 matching lines @@
     ]
   }
 }
 
 foreach(icon_name, _icon_names) {
   material_component_icon_bundle("material_component_${icon_name}_bundle") {
     visibility = [ ":material_components_ios" ]
     icon_name = "$icon_name"
   }
 }