MD Settings: methods to get root pages and sections

chrome/browser/resources/settings/settings_main/compiled_resources2.gyp

 # 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.
 {
   'targets': [
     {
       'target_name': 'settings_main',
       'dependencies': [
         '../compiled_resources2.gyp:route',
         '../compiled_resources2.gyp:search_settings',
+        '../about_page/compiled_resources2.gyp:about_page',
+        '../advanced_page/compiled_resources2.gyp:advanced_page',
+        '../basic_page/compiled_resources2.gyp:basic_page',
         '../settings_page/compiled_resources2.gyp:main_page_behavior',
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:assert',
         '../settings_page/compiled_resources2.gyp:settings_page_visibility',
         '../settings_ui/compiled_resources2.gyp:settings_ui_types',
       ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
   ],
 }