1e928c53_nsIChannel___Mozilla___MDN__2
[0] originalURI [1] nsIURI [2] 
The original URI used to construct the channel. This is used in the case of a redirect or URI "resolution" (For example resolving a resource: URI to a file: URI) so that the original pre-redirect URI can still be obtained. This is also used as the RI of the document resulting from the channel, unless the channel has the LOAD_REPLACE flag set. This is never null. Attempts to set it to null must throw. Note: This is distinctly different from the http Referer (referring URI), which is typically the page that contained the original URI (accessible from nsIHttpChannel.)
nsIChannel - Mozilla | MDN