gn: Remove unnecessary v8 defaults

content/shell/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/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build/config/win/console_app.gni")
 import("//build/config/win/manifest.gni")
 import("//media/media_options.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//tools/grit/repack.gni")
 import("//tools/grit/grit_rule.gni")
 if (is_android) {
   import("//build/config/android/config.gni")
 } else if (is_mac) {
   import("//build/config/mac/rules.gni")
-  import("//build_overrides/v8.gni")
   import("//build/mac/tweak_info_plist.gni")
+  import("//v8/gni/v8.gni")
 } else if (is_win) {
   import("//build/win/syzygy/syzygy.gni")
 }
 
 declare_args() {
   content_shell_product_name = "Content Shell"
   content_shell_version = "99.77.34.5"
 }
 
 config("content_shell_lib_warnings") {
@@ skipping 703 matching lines @@
       "{{bundle_resources_dir}}/{{source_file_part}}",
     ]
   }
 }
 
 mojom("mojo_bindings") {
   sources = [
     "common/layout_test/layout_test_bluetooth_fake_adapter_setter.mojom",
   ]
 }