Bug 155943 "Restore Properties" is always enabled for extended chart
Steps to reproduce: 1.New a report, includes a library, extends lib.chart 2.Choose the chart Expected result: "Restore Properties" is disabled untill set/change any local properties for the chart Actual result: "Restore Properties" is always enabled
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
assert prop != null;
		assert prop.getTypeCode( ) == PropertyType.STRUCT_TYPE && prop.isList( );
		List list = (List) obj.getLocalProperty( getModule( ), prop );
		if ( list == null || list.size( ) == 0 )
			return;
		writer.startElement( DesignSchemaConstants.LIST_PROPERTY_TAG );
		writer.attribute( DesignSchemaConstants.NAME_ATTRIB, memberName );
		Iterator iter = list.iterator( );
		while ( iter.hasNext( ) )
		{
			IStructure struct = (IStructure) iter.next( );
			writer.startElement( DesignSchemaConstants.STRUCTURE_TAG );
			Iterator memberIter = prop.getStructDefn( ).propertiesIterator( );
			while ( memberIter.hasNext( ) )
			{
				PropertyDefn memberDefn = (PropertyDefn) memberIter.next( );
				property( struct, memberDefn.getName( ) );
			}
			writer.endElement( );
		}
		writer.endElement( );
	}
	/**
	 * Writes user property definitions.
	 * 
	 * @param obj
	 *            the element that contains user properties
	 */
	protected void writeUserPropertyDefns( DesignElement obj )
	{