Use views::style for buttons, bootstrap ash_typography to do so.

ash/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("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 
 # Historical note: Ash shipped on Windows for a couple years to support
@@ skipping 42 matching lines @@
     "app_list/app_list_presenter_delegate_factory.h",
     "ash_constants.cc",
     "ash_constants.h",
     "ash_export.h",
     "ash_layout_constants.cc",
     "ash_layout_constants.h",
     "ash_switches.cc",
     "ash_switches.h",
     "ash_touch_exploration_manager_chromeos.cc",
     "ash_touch_exploration_manager_chromeos.h",
+    "ash_typography.cc",
+    "ash_typography.h",
     "ash_view_ids.h",
     "aura/aura_layout_manager_adapter.cc",
     "aura/aura_layout_manager_adapter.h",
     "aura/key_event_watcher_aura.cc",
     "aura/key_event_watcher_aura.h",
     "aura/pointer_watcher_adapter.cc",
     "aura/pointer_watcher_adapter.h",
     "aura/wm_shell_aura.cc",
     "aura/wm_shell_aura.h",
     "autoclick/autoclick_controller.cc",
@@ skipping 1418 matching lines @@
     "//content/public/app:both",
     "//device/bluetooth",
   ]
 
   data_deps = [
     "//ash/strings:ash_test_strings",
     "//ash/resources:ash_test_resources_with_content_100_percent",
     "//ash/resources:ash_test_resources_200_percent",
   ]
 }