display: bottom mode does not handle correctly mouse scroll

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Use the demo page, and if necessary resize the window to make page height 
greater than window height
2. Click on the input type date and make the bottom-up scroll control appear.
3. Now use mouse wheel to scroll the page. You'll notice that the bottom-up 
control doesn't stay fixed on the page

What is the expected output? What do you see instead?
The bottom-up control doesn't stay fixed on the page. It should.

What version of the product are you using? On what operating system?
Lastest version.

Please provide any additional information below.
The fix is quite simple: add a css "display: fixed" to the panel. 

Original issue reported on code.google.com by [email protected] on 29 Oct 2012 at 7:39