Removes the IsReadingListEnabled flags

ios/chrome/browser/ui/tools_menu/BUILD.gn

 # 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.
 
 source_set("tools_menu") {
   sources = [
     "reading_list_menu_view_item.h",
     "reading_list_menu_view_item.mm",
     "tools_menu_configuration.h",
     "tools_menu_configuration.mm",
     "tools_menu_constants.h",
     "tools_menu_constants.mm",
     "tools_menu_model.h",
     "tools_menu_model.mm",
     "tools_menu_view_controller.h",
     "tools_menu_view_controller.mm",
     "tools_menu_view_item.h",
     "tools_menu_view_item.mm",
     "tools_menu_view_tools_cell.h",
     "tools_menu_view_tools_cell.mm",
     "tools_popup_controller.h",
     "tools_popup_controller.mm",
   ]
   deps = [
     "//base",
     "//base:i18n",
-    "//components/reading_list/core:flags",
     "//components/strings",
     "//ios/chrome/app/strings",
     "//ios/chrome/browser",
     "//ios/chrome/browser/ui",
     "//ios/chrome/browser/ui/colors",
     "//ios/chrome/browser/ui/commands",
     "//ios/chrome/browser/ui/popup_menu",
     "//ios/chrome/browser/ui/reading_list",
     "//ios/chrome/browser/ui/toolbar:resource_macros",
     "//ios/chrome/common",
@@ skipping 40 matching lines @@
     "//ios/chrome/browser/ui",
     "//ios/chrome/browser/ui:ui_internal",
     "//ios/chrome/browser/ui/toolbar",
     "//ios/chrome/test/earl_grey:test_support",
     "//ios/third_party/earl_grey",
     "//ios/web:test_support",
     "//ui/base",
   ]
   libs = [ "XCTest.framework" ]
 }