Componentize PrefSyncableService and support classes.

chrome/browser/prefs/pref_service_mock_factory.h

Index: chrome/browser/prefs/pref_service_mock_factory.h
diff --git a/chrome/browser/prefs/pref_service_mock_factory.h b/chrome/browser/prefs/pref_service_mock_factory.h
deleted file mode 100644
index ab9bc26243e3e0f6cbc73b2c2e27e9b961c4deea..0000000000000000000000000000000000000000
--- a/chrome/browser/prefs/pref_service_mock_factory.h
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright 2013 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 CHROME_BROWSER_PREFS_PREF_SERVICE_MOCK_FACTORY_H_
-#define CHROME_BROWSER_PREFS_PREF_SERVICE_MOCK_FACTORY_H_
-
-#include "chrome/browser/prefs/pref_service_syncable_factory.h"
-
-// A helper that allows convenient building of custom PrefServices in tests.
-class PrefServiceMockFactory : public PrefServiceSyncableFactory {
- public:
-  PrefServiceMockFactory();
-  ~PrefServiceMockFactory() override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(PrefServiceMockFactory);
-};
-
-#endif  // CHROME_BROWSER_PREFS_PREF_SERVICE_MOCK_FACTORY_H_