Responsive image doesn't render on page load in Chrome, renders on browser resize or opening dev tools

Question

I am having a strange issue with an img that only renders when the browser gets resized or dev tools are opened. The img has srcset and sizes attributes, and is inside a polymer template. It displays normally whithout the attributes, or outside of the Polymer shadow dom. The issue came up with Chrome 39, I believe, and is restricted to Google Chrome, where there are no polyfills at work anymore. There are no errors in the console, naturally, status is 200 ok there. I am having no issues in Firefox or IE. My polymer version is 0.5.0, and I reported the issue at the Polymer github page, but maybe there is something else to it. Lex

Answer 1

OK, I think I may have fixed this, though it is a bit silly that I had to do it this way. Originally I had written these with the combined declaration:

background: url(image-name.jpg) top center fixed;

When I write it long form it seems to work just fine.

    background-image: url(image-name.jpg);
    background-position: top center;
    background-attachment: fixed;

If I have more time to look into it, I'll comment in any info I find on why this may be.