Make the DatabaseTracker thread-safe.

WebCore/platform/sql/SQLiteDatabase.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 30 matching lines @@
 const int SQLResultOk = SQLITE_OK;
 const int SQLResultRow = SQLITE_ROW;
 const int SQLResultSchema = SQLITE_SCHEMA;
 const int SQLResultFull = SQLITE_FULL;
 
 
 SQLiteDatabase::SQLiteDatabase()
     : m_db(0)
     , m_pageSize(-1)
     , m_transactionInProgress(false)
+    , m_sharable(false)
     , m_openingThread(0)
 {
 }
 
 SQLiteDatabase::~SQLiteDatabase()
 {
     close();
 }
 
 bool SQLiteDatabase::open(const String& filename)
@@ skipping 299 matching lines @@
 {
     m_lockingMutex.unlock();
 }
 
 bool SQLiteDatabase::isAutoCommitOn() const
 {
     return sqlite3_get_autocommit(m_db);
 }
 
 } // namespace WebCore