Instances of this component write UI into the display page. This component
 is trusted so can access preferences etc, but page content isn't and so
[scriptable, uuid(67003393-018c-4e96-af10-c6c51a049fad)]
interface nsIFeedWriter : nsISupports


 Uninitialize the feed writer.
void close()
 Initializes the feed writer and loads the feed subscription UI.
 @param  aWindow
         The DOMWindow of the preview page.
         window.location.href == the URI of the feed.
void init(in nsIDOMWindow aWindow)
 Writes the feed content, assumes that the feed writer is initialized.
void writeContent()