Move content settings extension API to content_settings dir.

chrome/browser/content_settings/extension_content_settings_helpers.h

 // Copyright (c) 2011 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_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__
-#define CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__
+#ifndef CHROME_BROWSER_CONTENT_SETTINGS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__
+#define CHROME_BROWSER_CONTENT_SETTINGS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__
 #pragma once
 
 #include <string>
 
 #include "chrome/common/content_settings.h"
 #include "chrome/common/content_settings_pattern.h"
 
 namespace extension_content_settings_helpers {
 
 // Parses an extension match pattern and returns a corresponding
@@ skipping 15 matching lines @@
 // Converts a content setting string to the corresponding ContentSetting.
 // Returns true if |setting_str| specifies a valid content setting,
 // false otherwise.
 bool StringToContentSetting(const std::string& setting_str,
                             ContentSetting* setting);
 // Returns a string representation of a ContentSetting.
 const char* ContentSettingToString(ContentSetting setting);
 
 }  // namespace extension_content_settings_helpers
 
-#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__
+#endif  // CHROME_BROWSER_CONTENT_SETTINGS_EXTENSION_CONTENT_SETTINGS_HELPERS_H__