Use extension match pattern syntax in content settings extension API

chrome/browser/extensions/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__
 #pragma once
 
 #include <string>
 
+#include "chrome/browser/content_settings/content_settings_pattern.h"
 #include "chrome/common/content_settings.h"
 
 namespace extension_content_settings_helpers {
 
+// Parses an extension match pattern and returns a corresponding
+// content settings pattern object.
+// If |pattern_str| is invalid or can't be converted to a content settings
+// pattern, |error| is set to the parsing error and an invalid pattern
+// is returned.
+ContentSettingsPattern ParseExtensionPattern(const std::string& pattern_str,
+                                             std::string* error);
+
 // Converts a content settings type string to the corresponding
 // ContentSettingsType. Returns CONTENT_SETTINGS_TYPE_DEFAULT if the string
 // didn't specify a valid content settings type.
 ContentSettingsType StringToContentSettingsType(
     const std::string& content_type);
 // Returns a string representation of a ContentSettingsType.
 const char* ContentSettingsTypeToString(ContentSettingsType type);
 
 // 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__