Remove unnecesary usage of RefPtr and PassRefPtr of DatabaseContext.

Source/modules/webdatabase/DatabaseBackendBase.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  * Copyright (C) 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.
@@ skipping 182 matching lines @@
 
     return guid;
 }
 
 // static
 const char* DatabaseBackendBase::databaseInfoTableName()
 {
     return infoTableName;
 }
 
-DatabaseBackendBase::DatabaseBackendBase(PassRefPtr<DatabaseContext> databaseContext, const String& name,
+DatabaseBackendBase::DatabaseBackendBase(DatabaseContext* databaseContext, const String& name,
     const String& expectedVersion, const String& displayName, unsigned long estimatedSize, DatabaseType databaseType)
     : m_databaseContext(databaseContext)
     , m_name(name.isolatedCopy())
     , m_expectedVersion(expectedVersion.isolatedCopy())
     , m_displayName(displayName.isolatedCopy())
     , m_estimatedSize(estimatedSize)
     , m_guid(0)
     , m_opened(false)
     , m_new(false)
     , m_isSyncDatabase(databaseType == DatabaseType::Sync)
@@ skipping 451 matching lines @@
 {
     executionContext()->addConsoleMessage(StorageMessageSource, ErrorMessageLevel, message);
 }
 
 ExecutionContext* DatabaseBackendBase::executionContext() const
 {
     return databaseContext()->executionContext();
 }
 
 } // namespace WebCore