Introduce //components/user_prefs, use to eliminate c/b/prefs dependency in Autofill.

chrome/browser/media/media_capture_devices_dispatcher.cc

 // Copyright (c) 2012 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 "chrome/browser/media/media_capture_devices_dispatcher.h"
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/media/audio_stream_indicator.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/media_devices_monitor.h"
 #include "content/public/common/media_stream_request.h"
 
 using content::BrowserThread;
 using content::MediaStreamDevices;
 
 namespace {
 
 const content::MediaStreamDevice* FindDefaultDeviceWithId(
@@ skipping 209 matching lines @@
     int render_process_id,
     int render_view_id,
     const content::MediaStreamDevice& device,
     content::MediaRequestState state) {
   FOR_EACH_OBSERVER(Observer, observers_,
                     OnRequestUpdate(render_process_id,
                                     render_view_id,
                                     device,
                                     state));
 }