Remove extension-to-component migration mechanism

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 861 matching lines @@
       "task_manager/task_manager_table_model.cc",
       "task_manager/task_manager_table_model.h",
       "toolbar/app_menu_icon_controller.cc",
       "toolbar/app_menu_icon_controller.h",
       "toolbar/app_menu_model.cc",
       "toolbar/app_menu_model.h",
       "toolbar/back_forward_menu_model.cc",
       "toolbar/back_forward_menu_model.h",
       "toolbar/bookmark_sub_menu_model.cc",
       "toolbar/bookmark_sub_menu_model.h",
+      "toolbar/component_action_delegate.h",
       "toolbar/component_toolbar_actions_factory.cc",
       "toolbar/component_toolbar_actions_factory.h",
       "toolbar/recent_tabs_sub_menu_model.cc",
       "toolbar/recent_tabs_sub_menu_model.h",
       "toolbar/toolbar_action_view_controller.h",
       "toolbar/toolbar_action_view_delegate.h",
       "toolbar/toolbar_actions_bar.cc",
       "toolbar/toolbar_actions_bar.h",
       "toolbar/toolbar_actions_bar_bubble_delegate.h",
       "toolbar/toolbar_actions_bar_delegate.h",
@@ skipping 2614 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" ]
   }
 }