[sql] Callback and scoped-ignore tests for sql::Statement.

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/files/file_path.h"
 #include "base/file_util.h"
@@ skipping 783 matching lines @@
 int Connection::OnSqliteError(int err, sql::Statement *stmt) {
   UMA_HISTOGRAM_SPARSE_SLOWLY("Sqlite.Error", err);
   AddTaggedHistogram("Sqlite.Error", err);
 
   // Always log the error.
   LOG(ERROR) << "sqlite error " << err
              << ", errno " << GetLastErrno()
              << ": " << GetErrorMessage();
 
   if (!error_callback_.is_null()) {
-    error_callback_.Run(err, stmt);
+    // Fire from a copy of the callback in case of reentry into

[erikwright (departed), 2013/07/05 19:16:55]

I would argue that this is a bug in Callback.

Should the storage _really_ be freed while invoking the method? I'd argue that
it should be temporarily add-ref'd.

Suggestion: ask ajwong@ for his opinion.

[Scott Hess - ex-Googler, 2013/07/08 21:15:35]

I had logged http://crbug.com/254584 , but since I've not seen any action on it
I'll follow up in case it hit a filter.

+    // re/set_error_callback().
+    ErrorCallback(error_callback_).Run(err, stmt);
     return err;
   }
 
   // The default handling is to assert on debug and to ignore on release.
   if (!ShouldIgnore(err))
     DLOG(FATAL) << GetErrorMessage();
   return err;
 }
 
 // TODO(shess): Allow specifying integrity_check versus quick_check.
@@ skipping 25 matching lines @@
   }
 
   // Best effort to put things back as they were before.
   const char kNoWritableSchema[] = "PRAGMA writable_schema = OFF";
   ignore_result(Execute(kNoWritableSchema));
 
   return ret;
 }
 
 }  // namespace sql