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

chrome/browser/media/media_stream_devices_controller.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_stream_devices_controller.h"
 
 #include "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "base/values.h"
 #include "chrome/browser/content_settings/content_settings_provider.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/content_settings/tab_specific_content_settings.h"
 #include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
 #include "chrome/browser/extensions/api/tab_capture/tab_capture_registry_factory.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.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/browser/ui/browser.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/content_settings.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/common/media_stream_request.h"
 
 using content::BrowserThread;
 
 namespace {
 
 bool HasAnyAvailableDevice() {
   const content::MediaStreamDevices& audio_devices =
       MediaCaptureDevicesDispatcher::GetInstance()->GetAudioCaptureDevices();
@@ skipping 292 matching lines @@
   }
   if (webcam_requested_) {
     profile_->GetHostContentSettingsMap()->SetContentSetting(
         primary_pattern,
         ContentSettingsPattern::Wildcard(),
         CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA,
         std::string(),
         content_setting);
   }
 }