[Ozone-Dri] Decouple the IO helper thread from DriWrapper

ui/ozone/platform/dri/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/linux/pkg_config.gni")
 import("//ui/ozone/ozone.gni")
 
 pkg_config("libdrm") {
   packages = [ "libdrm" ]
 }
@@ skipping 40 matching lines @@
     "dri_wrapper.cc",
     "dri_wrapper.h",
     "hardware_display_controller.cc",
     "hardware_display_controller.h",
     "hardware_display_plane.cc",
     "hardware_display_plane.h",
     "hardware_display_plane_manager.cc",
     "hardware_display_plane_manager.h",
     "hardware_display_plane_manager_legacy.cc",
     "hardware_display_plane_manager_legacy.h",
+    "io_helper_thread.cc",
+    "io_helper_thread.h",
     "native_display_delegate_dri.cc",
     "native_display_delegate_dri.h",
     "native_display_delegate_proxy.cc",
     "native_display_delegate_proxy.h",
     "overlay_plane.cc",
     "overlay_plane.h",
     "scoped_drm_types.cc",
     "scoped_drm_types.h",
     "screen_manager.cc",
     "screen_manager.h",
@@ skipping 79 matching lines @@
       ":dri_common",
       "//base",
       "//skia",
       "//ui/events/ozone:events_ozone_evdev",
       "//ui/events/ozone:events_ozone_layout",
     ]
 
     public_configs = [ ":libgbm" ]
   }
 }