Lazyily Load Images on Webkit Browsers and the Image Input Element

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Enable lazyload_images filter
2. Load a webpage within the mod_pagespeed enabled site with an image input 
element <input type="image"... - Particularly when using png files, haven't 
checked JPEGs - could be a rewrite_images issues
3. Scroll up and down the page, weeping as you notice the png files are not 
loaded, regardless of what you do to your htaccess file. Disable layload_images 
and cry in your pillow at night after seeing the incredible pagespeeds you 
could have but cannot

What is the expected output? What do you see instead?
I expect to see the png file loaded

What version of the product are you using (please check X-Mod-Pagespeed
header)?
pagespeed 0.10.21.2-1427

On what operating system?
Linux Fedora 15

Which version of Apache?
Apache/2.2.21

Which MPM?
Prefork

Please provide any additional information below, especially a URL or an
HTML file that exhibits the problem.
I would, but I'm not turning this filter on due to the nature of my 
configuration. Drupal CMS with a multisite install.

Original issue reported on code.google.com by a...@sageage1.com on 24 Feb 2012 at 8:21