Use MDCTypography instead of MDFRobotoFontLoader directly.

ios/showcase/core/app_delegate.mm

Index: ios/showcase/core/app_delegate.mm
diff --git a/ios/showcase/core/app_delegate.mm b/ios/showcase/core/app_delegate.mm
index 5fdc49347734b1f387baa5acd6627cfeb25e8e64..12f1a43cf49fecd9bb838ca5b8c4dc01d3f6f98f 100644
--- a/ios/showcase/core/app_delegate.mm
+++ b/ios/showcase/core/app_delegate.mm
@@ -9,8 +9,6 @@
 #import "ios/showcase/core/showcase_model.h"
 #import "ios/showcase/core/showcase_view_controller.h"
 #import "ios/third_party/material_components_ios/src/components/Typography/src/MaterialTypography.h"
-#import "ios/third_party/material_roboto_font_loader_ios/src/src/MDCTypographyAdditions/MDFRobotoFontLoader+MDCTypographyAdditions.h"
-#import "ios/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
 #include "ui/base/resource/resource_bundle.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
@@ -25,7 +23,6 @@
   base::MakeUnique<IOSChromeMain>();
   ResourceBundle::InitSharedInstanceWithLocale(
       std::string(), nullptr, ResourceBundle::LOAD_COMMON_RESOURCES);
-  [MDCTypography setFontLoader:[MDFRobotoFontLoader sharedInstance]];
   self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
   ShowcaseViewController* viewController =
       [[ShowcaseViewController alloc] initWithRows:[self rowsToDisplay]];