Bug 137176 It takes unacceptable long time to render a report
Description: Get the attached report design, preview in report designer. It takes unacceptable long time to render a report, and users could not get the output finally. Even during the rending, the computer could not do anything else.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
{
			if ( reportDesignDocFile.lastModified( ) > reportDocFile
					.lastModified( )
					|| ParameterAccessor.isOverwrite( request ) )
			{
				reportDocFile.delete( );
			}
		}
	}
	/**
	 * Get report service instance.
	 */
	protected IViewerReportService getReportService( )
	{
		return BirtReportServiceFactory.getReportService( );
	}
	/**
	 * Clear our resources.
	 * 
	 * @exception Throwable
	 * @return
	 */
	protected void __finalize( ) throws Throwable
	{
	}
	/**
	 * get parameter object.
	 * 
	 * @param request
	 * @param parameterObj