Move app/sql/* files to sql/ directory.

app/sql/diagnostic_error_delegate.h

-// Copyright (c) 2010 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 APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_
-#define APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_
-#pragma once
-
-#include "app/sql/connection.h"
-#include "base/logging.h"
-#include "base/metrics/histogram.h"
-
-namespace sql {
-
-// This class handles the exceptional sqlite errors that we might encounter
-// if for example the db is corrupted. Right now we just generate a UMA
-// histogram for release and an assert for debug builds.
-//
-// Why is it a template you ask? well, that is a funny story. The histograms
-// need to be singletons that is why they are always static at the function
-// scope, but we cannot use the Singleton class because they are not default
-// constructible. The template parameter makes the compiler to create unique
-// classes that don't share the same static variable.
-template <class UniqueT>
-class DiagnosticErrorDelegate : public ErrorDelegate {
- public:
-
-  virtual int OnError(int error, Connection* connection,
-                      Statement* stmt) {
-    NOTREACHED() << "sqlite error " << error
-                 << ", errno " << connection->GetLastErrno()
-                 << ": " << connection->GetErrorMessage();
-    RecordErrorInHistogram(error);
-    return error;
-  }
-
- private:
-  static void RecordErrorInHistogram(int error) {
-    // Trim off the extended error codes.
-    error &= 0xff;
-
-    // The histogram values from sqlite result codes go currently from 1 to
-    // 26 currently but 50 gives them room to grow.
-    UMA_HISTOGRAM_ENUMERATION(UniqueT::name(), error, 50);
-  }
-};
-
-}  // namespace sql
-
-#endif  // APP_SQL_DIAGNOSTIC_ERROR_DELEGATE_H_