Move gn _run target generation into test().

ui/accessibility/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("//build/config/ui.gni")
 import("//build/json_schema_api.gni")
 import("//testing/test.gni")
 if (is_android) {
   import("//build/config/android/rules.gni")
@@ skipping 108 matching lines @@
     "platform/test_ax_node_wrapper.h",
     "tree_generator.cc",
     "tree_generator.h",
   ]
 
   deps = [
     ":accessibility",
   ]
 }
 
-# TODO(GYP): Delete this after we've converted everything to GN.
-# The _run targets exist only for compatibility w/ GYP.
-group("accessibility_unittests_run") {
-  testonly = true
-  deps = [
-    ":accessibility_unittests",
-  ]
-}
-
 test("accessibility_unittests") {
   sources = [
     "ax_generated_tree_unittest.cc",
     "ax_text_utils_unittest.cc",
     "ax_tree_serializer_unittest.cc",
     "ax_tree_unittest.cc",
     "platform/ax_platform_node_win_unittest.cc",
   ]
 
   deps = [
@@ skipping 15 matching lines @@
 json_schema_api("ax_gen") {
   sources = [
     "ax_enums.idl",
   ]
   deps = [
     "//base/third_party/dynamic_annotations",
   ]
   root_namespace = "ui"
   schemas = true
 }