Unintended change in AdWords Flash to HTML5 conversion
I would recommend to export as HTML5 from Flash directly instead of relying on Googles conversion.
This has to do with how the Google conversion is animating this. It's probably based on an HTML5 canvas which can have Anti Aliasing disabled in certain events to improve performance.
Google maybe also enforce this to have a pleasant web performance for users. Flash has generally very poor performance because of things like that.

You might want to ask this on Stackoverflow instead, this is more a web programming question.