Implementing sign-in promo histograms for settings

ios/chrome/browser/ui/settings/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.
 
 bundle_data("resources") {
   sources = [
     "resources/app_icon_placeholder.png",
     "resources/app_icon_placeholder@2x.png",
     "resources/app_icon_placeholder@3x.png",
     "resources/encryption_error.png",
@@ skipping 103 matching lines @@
     "//components/content_settings/core/common",
     "//components/google/core/browser",
     "//components/handoff",
     "//components/history/core/browser",
     "//components/image_fetcher/ios",
     "//components/keyed_service/core",
     "//components/metrics",
     "//components/password_manager/core/browser",
     "//components/password_manager/core/common",
     "//components/physical_web/data_source",
+    "//components/pref_registry",
     "//components/prefs",
     "//components/resources",
     "//components/search_engines",
     "//components/signin/core/browser",
     "//components/signin/core/common",
     "//components/signin/ios/browser",
     "//components/strings",
     "//components/sync",
     "//components/translate/core/browser",
     "//components/translate/core/common",
@@ skipping 249 matching lines @@
     "//ios/web/public/test/http_server",
     "//net",
     "//ui/base",
     "//url",
   ]
   libs = [
     "UIKit.framework",
     "XCTest.framework",
   ]
 }