Refactor the DB code to make all DB layout tests pass on test_shell....

webkit/tools/test_shell/simple_database_system.h

Index: webkit/tools/test_shell/simple_database_system.h
===================================================================
--- webkit/tools/test_shell/simple_database_system.h	(revision 0)
+++ webkit/tools/test_shell/simple_database_system.h	(revision 0)
@@ -0,0 +1,38 @@
+// Copyright (c) 2009 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 WEBKIT_TOOLS_TEST_SHELL_SIMPLE_DATABASE_SYSTEM_H_
+#define WEBKIT_TOOLS_TEST_SHELL_SIMPLE_DATABASE_SYSTEM_H_
+
+#include "base/file_path.h"
+#include "base/platform_file.h"
+#include "base/scoped_temp_dir.h"
+
+class SimpleDatabaseSystem {
+ public:
+  static SimpleDatabaseSystem* GetInstance();
+  SimpleDatabaseSystem();
+  ~SimpleDatabaseSystem();
+
+  base::PlatformFile OpenFile(
+      const FilePath& file_name, int desired_flags,
+      base::PlatformFile* dir_handle);
+  int DeleteFile(const FilePath& file_name, bool sync_dir);
+  long GetFileAttributes(const FilePath& file_name);
+  long long GetFileSize(const FilePath& file_name);
+  void ClearAllDatabases();
+
+ private:
+  FilePath GetDBDir();
+  FilePath GetDBFileFullPath(const FilePath& file_name);
+
+  static SimpleDatabaseSystem* instance_;
+
+  ScopedTempDir temp_dir_;
+
+  // HACK: see OpenFile's implementation
+  base::PlatformFile hack_main_db_handle_;
+};
+
+#endif  // WEBKIT_TOOLS_TEST_SHELL_SIMPLE_DATABASE_SYSTEM_H_