Add Material Typography Schemes to MDC BUILD.gn.

Bug: 839445
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: I5193b544cc3e6db8d03b40d807c7d7f93dea94a5
Reviewed-on: https://chromium-review.googlesource.com/1043267Reviewed-by: Mohammad Refaat <mrefaat@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Daniel Blakemore <danblakemore@google.com>
Cr-Commit-Position: refs/heads/master@{#555905}

ios/third_party/material_components_ios/BUILD.gn

@@ -287,6 +287,11 @@ source_set("material_components_ios") {
     "src/components/schemes/Color/src/MDCSemanticColorScheme.h",
     "src/components/schemes/Color/src/MDCSemanticColorScheme.m",
     "src/components/schemes/Color/src/MaterialColorScheme.h",
+    "src/components/schemes/Typography/src/MDCLegacyFontScheme.h",
+    "src/components/schemes/Typography/src/MDCLegacyFontScheme.m",
+    "src/components/schemes/Typography/src/MDCTypographyScheme.h",
+    "src/components/schemes/Typography/src/MDCTypographyScheme.m",
+    "src/components/schemes/Typography/src/MaterialTypographyScheme.h",
   ]
   include_dirs = [
     "src/components/ActivityIndicator/src",