[iOS] Add experimental new keyboard accessory view.

ios/chrome/browser/ui/fancy_ui/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.
 
 source_set("fancy_ui") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "bidi_container_view.h",
     "bidi_container_view.mm",
+    "colored_button.h",
+    "colored_button.mm",
     "primary_action_button.h",
     "primary_action_button.mm",
-    "tinted_button.h",
-    "tinted_button.mm",
   ]
   deps = [
     "//base",
     "//base:i18n",
     "//ios/chrome/browser/ui/colors",
   ]
   public_deps = [
     "//ios/third_party/material_components_ios",
   ]
   libs = [ "UIKit.framework" ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "bidi_container_view_unittest.mm",
   ]
   deps = [
     ":fancy_ui",
     "//base",
     "//base:i18n",
     "//testing/gtest",
   ]
   configs += [ "//build/config/compiler:enable_arc" ]
 }