[sql] Use IGNORE conflict resolution in recovery.

sql/recovery.h

 // Copyright 2013 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 SQL_RECOVERY_H_
 #define SQL_RECOVERY_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 97 matching lines @@
   // NOTE(shess): Only call this when adding recovery support.  In the
   // steady state, all databases should progress to recovered or razed.
   static void Rollback(scoped_ptr<Recovery> r);
 
   // Handle to the temporary recovery database.
   sql::Connection* db() { return &recover_db_; }
 
   // Attempt to recover the named table from the corrupt database into
   // the recovery database using a temporary recover virtual table.
   // The virtual table schema is derived from the named table's schema
-  // in database [main].  Data is copied using INSERT OR REPLACE, so
-  // duplicates overwrite each other.
+  // in database [main].  Data is copied using INSERT OR IGNORE, so
+  // duplicates are dropped.
   //
   // If the source table has fewer columns than the target, the target
   // DEFAULT value will be used for those columns.
   //
   // Returns true if all operations succeeded, with the number of rows
   // recovered in |*rows_recovered|.
   //
   // NOTE(shess): Due to a flaw in the recovery virtual table, at this
   // time this code injects the DEFAULT value of the target table in
   // locations where the recovery table returns NULL.  This is not
@@ skipping 40 matching lines @@
 
   Connection* db_;         // Original database connection.
   Connection recover_db_;  // Recovery connection.
 
   DISALLOW_COPY_AND_ASSIGN(Recovery);
 };
 
 }  // namespace sql
 
 #endif  // SQL_RECOVERY_H_