Delete base/prefs and update callers to use components.

ios/chrome/browser/net/ios_chrome_http_user_agent_settings.cc

 // Copyright 2015 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.
 
 #include "ios/chrome/browser/net/ios_chrome_http_user_agent_settings.h"
 
-#include "base/prefs/pref_service.h"
+#include "components/prefs/pref_service.h"
 #include "ios/chrome/browser/pref_names.h"
 #include "ios/web/public/web_client.h"
 #include "ios/web/public/web_thread.h"
 #include "net/http/http_util.h"
 
 IOSChromeHttpUserAgentSettings::IOSChromeHttpUserAgentSettings(
     PrefService* prefs) {
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::UI);
   pref_accept_language_.Init(prefs::kAcceptLanguages, prefs);
   last_pref_accept_language_ = *pref_accept_language_;
@@ skipping 20 matching lines @@
         net::HttpUtil::GenerateAcceptLanguageHeader(new_pref_accept_language);
     last_pref_accept_language_ = new_pref_accept_language;
   }
   return last_http_accept_language_;
 }
 
 std::string IOSChromeHttpUserAgentSettings::GetUserAgent() const {
   DCHECK_CURRENTLY_ON_WEB_THREAD(web::WebThread::IO);
   return web::GetWebClient()->GetUserAgent(false);
 }