[sql] QuotaDatabase schema upgrade doesn't use transactions right.

sql/connection.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 "sql/connection.h"
 
 #include <string.h>
 
 #include "base/bind.h"
 #include "base/debug/dump_without_crashing.h"
@@ skipping 1121 matching lines @@
     // Mark the outermost transaction as needing rollback.
     needs_rollback_ = true;
     return;
   }
 
   DoRollback();
 }
 
 bool Connection::CommitTransaction() {
   if (!transaction_nesting_) {
-    DLOG_IF(FATAL, !poisoned_) << "Rolling back a nonexistent transaction";
+    DLOG_IF(FATAL, !poisoned_) << "Committing back a nonexistent transaction";
     return false;
   }
   transaction_nesting_--;
 
   if (transaction_nesting_ > 0) {
     // Mark any nested transactions as failing after we've already got one.
     return !needs_rollback_;
   }
 
   if (needs_rollback_) {
@@ skipping 647 matching lines @@
   ignore_result(Execute(kNoWritableSchema));
 
   return ret;
 }
 
 base::TimeTicks TimeSource::Now() {
   return base::TimeTicks::Now();
 }
 
 }  // namespace sql