Inline extensions .gypi files into GN build.

extensions/extensions_resources.gyp

-# 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.
-
-{
-  'targets': [
-    {
-      'target_name': 'extensions_resources',
-      'type': 'none',
-      'variables': {
-        'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/extensions',
-      },
-      'dependencies': [
-        'common/api/api.gyp:extensions_api_mojom',
-        '../device/serial/serial.gyp:device_serial_mojo',
-      ],
-      'actions': [
-        {
-          'action_name': 'generate_extensions_resources',
-          'variables': {
-            'grit_grd_file': 'extensions_resources.grd',
-          },
-          'includes': [ '../build/grit_action.gypi' ],
-        },
-        {
-          'action_name': 'generate_extensions_browser_resources',
-          'variables': {
-            'grit_grd_file': 'browser/resources/extensions_browser_resources.grd',
-          },
-          'includes': [ '../build/grit_action.gypi' ],
-        },
-        {
-          'action_name': 'generate_extensions_renderer_resources',
-          'variables': {
-            'grit_grd_file': 'renderer/resources/extensions_renderer_resources.grd',
-            'grit_additional_defines': [
-              '-E', 'mojom_root=<(SHARED_INTERMEDIATE_DIR)',
-            ],
-          },
-          'includes': [ '../build/grit_action.gypi' ],
-        },
-      ],
-      'includes': [ '../build/grit_target.gypi' ],
-    }
-  ]
-}