Remove obsolete keywords table migrating function

components/search_engines/keyword_table.h

 // Copyright 2014 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_SEARCH_ENGINES_KEYWORD_TABLE_H_
 #define COMPONENTS_SEARCH_ENGINES_KEYWORD_TABLE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 147 matching lines @@
   // Returns true on success.
   bool UpdateKeyword(const TemplateURLData& data);
 
   // Gets a string representation for keyword with id specified.
   // Used to store its result in |meta| table or to compare with another
   // keyword. Returns true on success, false otherwise.
   bool GetKeywordAsString(TemplateURLID id,
                           const std::string& table_name,
                           std::string* result);
 
-  // Migrates table |name| (which should be either "keywords" or
-  // "keywords_backup") from version 44 to version 45.
-  bool MigrateKeywordsTableForVersion45(const std::string& name);
-
   DISALLOW_COPY_AND_ASSIGN(KeywordTable);
 };
 
 #endif  // COMPONENTS_SEARCH_ENGINES_KEYWORD_TABLE_H_