Remove duplicated headers from modules/

Source/modules/webdatabase/DatabaseTask.cpp

 /*
  * Copyright (C) 2007, 2008, 2013 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 12 matching lines @@
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "config.h"
 #include "modules/webdatabase/DatabaseTask.h"
 
 #include "platform/Logging.h"
 #include "modules/webdatabase/Database.h"
-#include "modules/webdatabase/DatabaseBackend.h"
 
 namespace WebCore {
 
 DatabaseTaskSynchronizer::DatabaseTaskSynchronizer()
     : m_taskCompleted(false)
 #ifndef NDEBUG
     , m_hasCheckedForTermination(false)
 #endif
 {
 }
@@ skipping 151 matching lines @@
 }
 
 #if !LOG_DISABLED
 const char* DatabaseBackend::DatabaseTableNamesTask::debugTaskName() const
 {
     return "DatabaseTableNamesTask";
 }
 #endif
 
 } // namespace WebCore