Make sql::Connection::Raze() more robust against corruptions.

sql/connection_unittest.cc

 // 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.
 
 #include "base/file_util.h"
 #include "base/scoped_temp_dir.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
 #include "sql/meta_table.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 168 matching lines @@
   }
 
   {
     sql::Statement s(db().GetUniqueStatement("SELECT * FROM sqlite_master"));
     ASSERT_FALSE(s.Step());
   }
 
   {
     sql::Statement s(db().GetUniqueStatement("PRAGMA auto_vacuum"));
     ASSERT_TRUE(s.Step());
-    // auto_vacuum must be preserved across a Raze.
+    // The new database has the same auto_vacuum as a fresh database.
     EXPECT_EQ(pragma_auto_vacuum, s.ColumnInt(0));
   }
 }
 
 // Test that Raze() maintains page_size.
 TEST_F(SQLConnectionTest, RazePageSize) {
   // Fetch the default page size and double it for use in this test.
   // Scoped to release statement before Close().
   int default_page_size = 0;
   {
@@ skipping 88 matching lines @@
   // Otherwise, sqlite3 doesn't find the correct directory to store
   // temporary files and will report the error 'unable to open
   // database file'.
   ASSERT_TRUE(meta_table.Init(&db(), 4, 4));
 }
 #endif
 
 // TODO(shess): Spin up a background thread to hold other_db, to more
 // closely match real life.  That would also allow testing
 // RazeWithTimeout().