Adding the attribute referrer so that you can get the referrer from the channel once you have previously set it.

netwerk/protocol/http/public/nsIHTTPChannel.idl

@@ -77,6 +77,8 @@ interface nsIHTTPChannel : nsIChannel
     */
     void   SetReferrer(in nsIURI referrer, in unsigned long referrerLevel);
 
+	 readonly attribute nsIURI referrer;
+
     readonly attribute unsigned long ResponseStatus;
 
     readonly attribute string ResponseString;

netwerk/protocol/http/src/nsHTTPChannel.cpp

@@ -2044,6 +2044,8 @@ nsHTTPChannel::SetReferrer(nsIURI *referrer, PRUint32 referrerLevel)
     if (referrerLevel == 0)
         return NS_OK;
 
+    mReferrer = referrer;
+
     if (!referrer)
         return NS_ERROR_NULL_POINTER;
 
@@ -2059,6 +2061,16 @@ nsHTTPChannel::SetReferrer(nsIURI *referrer, PRUint32 referrerLevel)
     return NS_OK; 
 }
 
+NS_IMETHODIMP
+nsHTTPChannel::GetReferrer(nsIURI** aReferrer)
+{
+   NS_ENSURE_ARG_POINTER(aReferrer);
+
+   *aReferrer = mReferrer;
+   NS_IF_ADDREF(*aReferrer);
+   return NS_OK;
+}
+
 nsresult DupString(char* *o_Dest, const char* i_Src)
 {
     if (!o_Dest)

netwerk/protocol/http/src/nsHTTPChannel.h

@@ -127,6 +127,7 @@ public:
 protected:
     nsCOMPtr<nsIURI>                    mOriginalURI;
     nsCOMPtr<nsIURI>                    mURI;
+    nsCOMPtr<nsIURI>                    mReferrer;
     PRBool                              mConnected; 
     HTTPState                           mState;
     nsCOMPtr<nsIHTTPEventSink>          mEventSink;