[Ozone-Drm] Remove GPU lock

ui/ozone/platform/drm/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")
 
 declare_args() {
   use_mesa_platform_null = false
   use_drm_atomic = false
@@ skipping 29 matching lines @@
     "gpu/drm_gpu_display_manager.cc",
     "gpu/drm_gpu_display_manager.h",
     "gpu/drm_gpu_platform_support.cc",
     "gpu/drm_gpu_platform_support.h",
     "gpu/drm_surface.cc",
     "gpu/drm_surface.h",
     "gpu/drm_vsync_provider.cc",
     "gpu/drm_vsync_provider.h",
     "gpu/drm_window.cc",
     "gpu/drm_window.h",
-    "gpu/gpu_lock.cc",
-    "gpu/gpu_lock.h",
     "gpu/hardware_display_controller.cc",
     "gpu/hardware_display_controller.h",
     "gpu/hardware_display_plane.cc",
     "gpu/hardware_display_plane.h",
     "gpu/hardware_display_plane_manager.cc",
     "gpu/hardware_display_plane_manager.h",
     "gpu/hardware_display_plane_manager_legacy.cc",
     "gpu/hardware_display_plane_manager_legacy.h",
     "gpu/overlay_plane.cc",
     "gpu/overlay_plane.h",
@@ skipping 122 matching lines @@
     public_configs = [
       ":libgbm",
       "//third_party/khronos:khronos_headers",
     ]
 
     if (use_mesa_platform_null) {
       defines += [ "USE_MESA_PLATFORM_NULL" ]
     }
   }
 }