Make FaviconService::GetRawFaviconForPageURL() select the best candidate among all the icon types

components/history/core/browser/thumbnail_database.h

 // 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.
 
 #ifndef COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
@@ skipping 147 matching lines @@
   bool DeleteFavicon(favicon_base::FaviconID id);
 
   // Icon Mapping --------------------------------------------------------------
   //
   // Returns true if there is a matched icon mapping for the given page and
   // icon type.
   // The matched icon mapping is returned in the icon_mapping parameter if it is
   // not NULL.
 
   // Returns true if there are icon mappings for the given page and icon types.
-  // If |required_icon_types| contains multiple icon types and there is more
-  // than one matched icon type in the database, icons of only a single type
-  // will be returned in the priority of TOUCH_PRECOMPOSED_ICON, TOUCH_ICON,
-  // and FAVICON.
   // The matched icon mappings are returned in the |mapping_data| parameter if
   // it is not NULL.
   bool GetIconMappingsForPageURL(const GURL& page_url,
                                  int required_icon_types,
                                  std::vector<IconMapping>* mapping_data);
 
   // Returns true if there is any matched icon mapping for the given page.
   // All matched icon mappings are returned in descent order of IconType if
   // mapping_data is not NULL.
   bool GetIconMappingsForPageURL(const GURL& page_url,
@@ skipping 85 matching lines @@
 
   sql::Connection db_;
   sql::MetaTable meta_table_;
 
   HistoryBackendClient* backend_client_;
 };
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_THUMBNAIL_DATABASE_H_