title: Saving binary data in a browser without it getting UTF8 encoded on download
body: <p>My web app receives data in the form of a base64 encoded string, which is decodes using atob, and stores via URL.createObjectURL().  This data is then downloaded via the right-click save-as dialog.  The downloaded filed always matches the source file when the source file is ascii encoded.  However this isn't the case when the source file is just plain binary data.  A diff of a non ascii encoded downloaded file vs its source file appears to show that the downloaded file is UTF-8 encoded.  How can this problem be fixed?  Please note, I'm locked into using firefox 10.</p>