Implement extension controlled indicators, starting with New Tab page

chrome/browser/ui/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/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 1088 matching lines @@
       "webui/settings/font_handler.cc",
       "webui/settings/font_handler.h",
       "webui/settings/languages_handler.cc",
       "webui/settings/languages_handler.h",
       "webui/settings/md_settings_localized_strings_provider.cc",
       "webui/settings/md_settings_localized_strings_provider.h",
       "webui/settings/md_settings_ui.cc",
       "webui/settings/md_settings_ui.h",
       "webui/settings/metrics_reporting_handler.cc",
       "webui/settings/metrics_reporting_handler.h",
+      "webui/settings/on_startup_handler.cc",
+      "webui/settings/on_startup_handler.h",
       "webui/settings/people_handler.cc",
       "webui/settings/people_handler.h",
       "webui/settings/profile_info_handler.cc",
       "webui/settings/profile_info_handler.h",
       "webui/settings/protocol_handlers_handler.cc",
       "webui/settings/protocol_handlers_handler.h",
       "webui/settings/reset_settings_handler.cc",
       "webui/settings/reset_settings_handler.h",
       "webui/settings/safe_browsing_handler.cc",
       "webui/settings/safe_browsing_handler.h",
@@ skipping 2362 matching lines @@
       "test/test_confirm_bubble_model.cc",
       "test/test_confirm_bubble_model.h",
     ]
     deps += [ "//chrome/test:test_support_ui" ]
   }
 
   if (enable_extensions) {
     deps += [ "//extensions/browser" ]
   }
 }