This JSFL script adds the ability to export your MovieClips as CSS keyframes animations from Flash Pro CS6, so that they can run without any javascript in the browser.
The result is a PNG sprite sheet and a CSS file featuring a class that you simply apply to an html element to see the result.
Download CSS.plugin.jsfl and place it in Common/Configuration/Sprite Sheet Plugins/ inside the Flash Pro installation folder. You need to restart the application for the exporter to appear in the dialog.
Right-clic the element in your library and select "Generate Spritesheet". In the export dialog screen, be sure to select the appropriate data format.
The current version can only export ONE SINGLE SYMBOL at a time (don't select multiple MovieClips). I'm currently working on fixing that issue.
Thank you for your attention.
Credits: based on stock exporters from Flash CS6, modified by @boblemarin