nsIURIWithPrincipal is currently used to retrieve the nsIPrincipal from a
BlobURL object. BlobURLProtocolHandler has a hashtable containing, for each
blobURL, a BlobImpl and its nsIPrincipal. This patch introduces
BlobURLProtocolHandler::GetBlobURLPrincipal() that retrieves the nsIPrincipal
from this hashtable.
This patch fixes also a bug in how the revocation of blobURLs is broadcasted to
other processes. This should be done immediately because each process creates
its own timer to revoke them after 5 seconds.
An important change is related to NS_SecurityCompareURIs() where, if 1 (or
both) of the 2 URIs to compare, is a revoked BlobURL, we will QI its URL to
nsIStandardURL and fail out at that point.
