I'm not sure what do you mean by 'If I click download to PDF document'. Please, try the following steps:
- go to http://pdfcrowd.com/
- paste http://www.highcharts.com/demo/?example=pie-basic&theme=default to the conversion form's Address field
- click the Convert to PDF button and save the created PDF file
The created PDF should contain the pie chart. Does this work for you?