ozone: Remove GLImageOzoneNativePixmapDrm unittest.

ui/ozone/gl/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.
 
-import("//build/config/linux/pkg_config.gni")
 import("//testing/test.gni")
 
-if (target_os == "chromeos") {
-  pkg_config("libdrm") {
-    packages = [ "libdrm" ]
-  }
-}
-
 component("gl") {
   sources = [
     "gl_image_ozone_native_pixmap.cc",
     "gl_image_ozone_native_pixmap.h",
     "ozone_gl_export.h",
   ]
 
   defines = [ "OZONE_GL_IMPLEMENTATION" ]
 
   deps = [
     "//ui/gfx",
     "//ui/gl",
     "//ui/ozone:ozone_base",
   ]
 }
 
 test("ozone_gl_unittests") {
   sources = [
     "gl_image_ozone_native_pixmap_unittest.cc",
   ]
 
-  if (target_os == "chromeos" && target_cpu != "arm") {
-    sources += [ "gl_image_ozone_native_pixmap_drm_unittest.cc" ]
-  }
-
   deps = [
     "//base/test:test_support",
     "//testing/gtest",
     "//ui/gfx",
     "//ui/gl:run_all_unittests",
     "//ui/gl:test_support",
     "//ui/ozone",
   ]
 
-  if (target_os == "chromeos") {
-    configs += [ ":libdrm" ]
-  }
-
   data_deps = [
     "//third_party/mesa:osmesa",
   ]
 }