Revert of Delete base/prefs and update callers to use components.

ios/chrome/browser/net/ios_chrome_http_user_agent_settings.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_NET_IOS_CHROME_HTTP_USER_AGENT_SETTINGS_H_
 #define IOS_CHROME_BROWSER_NET_IOS_CHROME_HTTP_USER_AGENT_SETTINGS_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "components/prefs/pref_member.h"
+#include "base/prefs/pref_member.h"
 #include "net/url_request/http_user_agent_settings.h"
 
 class PrefService;
 
 // An implementation of |HttpUserAgentSettings| that provides HTTP header
 // Accept-Language value that tracks Pref settings.
 class IOSChromeHttpUserAgentSettings : public net::HttpUserAgentSettings {
  public:
   // Must be called on the UI thread.
   explicit IOSChromeHttpUserAgentSettings(PrefService* prefs);
@@ skipping 11 matching lines @@
 
   // Avoid re-processing by caching the last value from the preferences and the
   // last result of processing via net::HttpUtil::GenerateAccept*Header().
   mutable std::string last_pref_accept_language_;
   mutable std::string last_http_accept_language_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromeHttpUserAgentSettings);
 };
 
 #endif  // IOS_CHROME_BROWSER_NET_IOS_CHROME_HTTP_USER_AGENT_SETTINGS_H_