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 54 matching lines @@
     "common/accelerators/exit_warning_handler.cc",
     "common/accelerators/exit_warning_handler.h",
     "common/accessibility_delegate.h",
     "common/accessibility_types.h",
     "common/ash_constants.cc",
     "common/ash_constants.h",
     "common/ash_layout_constants.cc",
     "common/ash_layout_constants.h",
     "common/ash_switches.cc",
     "common/ash_switches.h",
+    "common/ash_typography.cc",
+    "common/ash_typography.h",
     "common/ash_view_ids.h",
     "common/cast_config_controller.cc",
     "common/cast_config_controller.h",
     "common/default_accessibility_delegate.cc",
     "common/default_accessibility_delegate.h",
     "common/devtools/ash_devtools_css_agent.cc",
     "common/devtools/ash_devtools_css_agent.h",
     "common/devtools/ash_devtools_dom_agent.cc",
     "common/devtools/ash_devtools_dom_agent.h",
     "common/drag_drop/drag_image_view.cc",
@@ skipping 1404 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",
   ]
 }