Make the DatabaseTracker thread-safe.

WebCore/storage/DatabaseTask.cpp

 /*
  * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
  *
  * 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 99 matching lines @@
 // *** DatabaseCloseTask ***
 // Closes the database.
 
 DatabaseCloseTask::DatabaseCloseTask(Database* database, DatabaseTaskSynchronizer* synchronizer)
     : DatabaseTask(database, synchronizer)
 {
 }
 
 void DatabaseCloseTask::doPerformTask()
 {
-    database()->close();
+    // Tell the database not to call back to the context thread; we'll handle it.
+    database()->close(false);
 }
 
 #ifndef NDEBUG
 const char* DatabaseCloseTask::debugTaskName() const
 {
     return "DatabaseCloseTask";
 }
 #endif
 
 // *** DatabaseTransactionTask ***
@@ skipping 43 matching lines @@
 #ifndef NDEBUG
 const char* DatabaseTableNamesTask::debugTaskName() const
 {
     return "DatabaseTableNamesTask";
 }
 #endif
 
 } // namespace WebCore
 
 #endif