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

chrome/browser/extensions/component_loader_unittest.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 <string>
 
 #include "chrome/browser/extensions/component_loader.h"
 
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "chrome/browser/extensions/test_extension_service.h"
-#include "chrome/browser/prefs/pref_registry_syncable.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/background_info.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_set.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_pref_service_syncable.h"
+#include "components/user_prefs/pref_registry_syncable.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using extensions::Extension;
 
 namespace {
 
 class MockExtensionService : public TestExtensionService {
  private:
   bool ready_;
   size_t unloaded_count_;
@@ skipping 282 matching lines @@
   EXPECT_EQ(default_count + 1, extension_service_.extensions()->size());
   EXPECT_EQ(0u, extension_service_.unloaded_count());
 
   // replace loaded component extension.
   component_loader_.AddOrReplace(known_extension);
   EXPECT_EQ(default_count + 1, extension_service_.extensions()->size());
   EXPECT_EQ(1u, extension_service_.unloaded_count());
 }
 
 }  // namespace extensions