Add components and CLD to GN build.

components/web_modal.gypi

 # Copyright (c) 2013 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': [
     {
+      # GN version: //components/web_modal
       'target_name': 'web_modal',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../content/content.gyp:content_browser',
         '../skia/skia.gyp:skia',
       ],
-      'defines': [
-        'WEB_MODAL_IMPLEMENTATION',
-      ],
       'sources': [
+        # Note: sources list duplicated in GN build.
         'web_modal/modal_dialog_host.cc',
         'web_modal/modal_dialog_host.h',
         'web_modal/native_web_contents_modal_dialog.h',
         'web_modal/single_web_contents_dialog_manager.h',
         'web_modal/web_contents_modal_dialog_host.cc',
         'web_modal/web_contents_modal_dialog_host.h',
         'web_modal/web_contents_modal_dialog_manager.cc',
         'web_modal/web_contents_modal_dialog_manager.h',
         'web_modal/web_contents_modal_dialog_manager_delegate.cc',
         'web_modal/web_contents_modal_dialog_manager_delegate.h',
       ],
     },
     {
+      # GN version: //components/web_modal:test_support
       'target_name': 'web_modal_test_support',
       'type': 'static_library',
       'dependencies': [
         'web_modal',
       ],
       'sources': [
+        # Note: sources list duplicated in GN build.
         'web_modal/test_web_contents_modal_dialog_host.cc',
         'web_modal/test_web_contents_modal_dialog_host.h',
         'web_modal/test_web_contents_modal_dialog_manager_delegate.cc',
         'web_modal/test_web_contents_modal_dialog_manager_delegate.h',
       ],
     },
   ],
 }