Refactors keyboard related code so mash can use a keyboard

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")
 
 assert(use_aura)
 assert(enable_hidpi)
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("ash.gyp") ],
                           "scope",
                           [ "ash.gyp" ])
 
 component("ash") {
   sources = gypi_values.ash_sources
+  sources += [
+    "keyboard/keyboard_ui_mus.cc",
+    "keyboard/keyboard_ui_mus.h",
+  ]
 
   configs += [ "//build/config:precompiled_headers" ]
-  defines = [ "ASH_IMPLEMENTATION" ]
+  defines = [
+    "ASH_IMPLEMENTATION",
+    "MOJO_SHELL_CLIENT",
+  ]
 
   public_deps = [
     "//ash/resources",
     "//ash/strings",
   ]
   deps = [
     "//base",
     "//base:i18n",
     "//base/third_party/dynamic_annotations",
     "//cc",
     "//components/device_event_log",
     "//components/onc",
     "//components/signin/core/account_id",
     "//components/user_manager",
     "//components/wallpaper",
     "//media",
+    "//mojo/public/c/system:for_component",
+    "//mojo/shell/public/cpp",
     "//net",
     "//skia",
     "//third_party/icu",
     "//ui/accessibility",
     "//ui/app_list",
     "//ui/aura",
     "//ui/base",
     "//ui/base:ui_data_pack",
     "//ui/base/ime",
     "//ui/compositor",
     "//ui/events",
     "//ui/events:events_base",
     "//ui/events:gesture_detection",
     "//ui/events/devices",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/keyboard",
+    "//ui/keyboard:mojom",
     "//ui/message_center",
     "//ui/platform_window/stub",
     "//ui/resources",
     "//ui/strings",
     "//ui/views",
     "//ui/wm",
     "//url",
   ]
 
   if (is_win) {
@@ skipping 343 matching lines @@
     configs += [ "//build/config/win:windowed" ]
     deps += [ "//sandbox" ]
   }
 
   if (is_chromeos) {
     deps += [ "//device/bluetooth" ]
   }
 }
 # When adding support for isolates, please have a look at run-time dependencies
 # in the ash_unittests_run target in ash.gyp.