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

chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_apitest.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 "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "chrome/browser/extensions/api/bookmark_manager_private/bookmark_manager_private_api.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "components/user_prefs/user_prefs.h"
 
 // Times out on win asan, http://crbug.com/166026
 #if defined(OS_WIN) && defined(ADDRESS_SANITIZER)
 #define MAYBE_BookmarkManager DISABLED_BookmarkManager
 #else
 #define MAYBE_BookmarkManager BookmarkManager
 #endif
 IN_PROC_BROWSER_TEST_F(ExtensionApiTest, MAYBE_BookmarkManager) {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kEnableExperimentalExtensionApis);
@@ skipping 10 matching lines @@
 
   // Provide some testing data here, since bookmark editing will be disabled
   // within the extension.
   BookmarkModel* model = BookmarkModelFactory::GetForProfile(profile);
   ui_test_utils::WaitForBookmarkModelToLoad(model);
   const BookmarkNode* bar = model->bookmark_bar_node();
   const BookmarkNode* folder = model->AddFolder(bar, 0, ASCIIToUTF16("Folder"));
   model->AddURL(bar, 1, ASCIIToUTF16("AAA"), GURL("http://aaa.example.com"));
   model->AddURL(folder, 0, ASCIIToUTF16("BBB"), GURL("http://bbb.example.com"));
 
-  PrefService* prefs = PrefServiceFromBrowserContext(profile);
+  PrefService* prefs = components::UserPrefs::Get(profile);
   prefs->SetBoolean(prefs::kEditBookmarksEnabled, false);
 
   ASSERT_TRUE(RunComponentExtensionTest("bookmark_manager/edit_disabled"))
       << message_;
 }