[sync] Add typed url sync metadata to the history db

components/history/core/browser/url_database.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_HISTORY_CORE_BROWSER_URL_DATABASE_H_
 #define COMPONENTS_HISTORY_CORE_BROWSER_URL_DATABASE_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 248 matching lines @@
   // index, which is faster than the reverse.
   //
   // is_temporary is false when generating the "regular" URLs table. The expirer
   // sets this to true to generate the  temporary table, which will have a
   // different name but the same schema.
   bool CreateURLTable(bool is_temporary);
 
   // Creates the index over URLs so we can quickly look up based on URL.
   bool CreateMainURLIndex();
 
+  // Recreate URL table, and keep all existing contents.
+  bool RecreateURLTableWithAllContents();
+
   // Ensures the keyword search terms table exists.
   bool InitKeywordSearchTermsTable();
 
   // Creates the indices used for keyword search terms.
   bool CreateKeywordSearchTermsIndices();
 
   // Deletes the keyword search terms table.
   bool DropKeywordSearchTermsTable();
 
   // Inserts the given URL row into the URLs table, using the regular table
@@ skipping 47 matching lines @@
 // is_null() then this function determines a new time threshold each time it is
 // called. Since getting system time can be costly (such as for cases where
 // this function will be called in a loop over many history items), you can
 // provide a non-null |time_cache| by simply initializing |time_cache| with
 // AutocompleteAgeThreshold() (or any other desired time in the past).
 bool RowQualifiesAsSignificant(const URLRow& row, const base::Time& threshold);
 
 }  // namespace history
 
 #endif  // COMPONENTS_HISTORY_CORE_BROWSER_URL_DATABASE_H_