Stream loader now saves principals from channel; needed for signed scripts. r=norris

(this is mstoltz's checkin)

netwerk/base/public/nsIStreamLoader.idl

@@ -55,6 +55,11 @@ interface nsIStreamLoader : nsISupports
      * Gets the number of bytes read so far.
      */
     readonly attribute unsigned long numBytesRead;
+
+    /**
+     * Gets the owner of this file
+     */
+    readonly attribute nsISupports owner;
 };
 
 %{C++

netwerk/base/src/nsStreamLoader.cpp

@@ -96,6 +96,14 @@ nsStreamLoader::GetNumBytesRead(PRUint32* aNumBytes)
   return NS_OK;
 }
 
+NS_IMETHODIMP 
+nsStreamLoader::GetOwner(nsISupports** aOwner)
+{
+  *aOwner = mOwner.get();
+  NS_IF_ADDREF(*aOwner);
+  return NS_OK;
+}
+
 NS_IMETHODIMP 
 nsStreamLoader::OnStartRequest(nsIChannel* channel, nsISupports *ctxt)
 {
@@ -106,6 +114,7 @@ NS_IMETHODIMP
 nsStreamLoader::OnStopRequest(nsIChannel* channel, nsISupports *ctxt,
                               nsresult status, const PRUnichar *errorMsg)
 {
+  (void)channel->GetOwner(getter_AddRefs(mOwner));
   nsresult rv = mObserver->OnStreamComplete(this, mContext, status, 
                                             mData.Length(), 
                                             mData.GetBuffer());

netwerk/base/src/nsStreamLoader.h

@@ -47,6 +47,7 @@ protected:
   nsCOMPtr<nsIStreamLoaderObserver> mObserver;
   nsCOMPtr<nsISupports>             mContext;  // the observer's context
   nsCString                         mData;
+  nsCOMPtr<nsISupports>             mOwner;
 ///  nsCOMPtr<nsILoadGroup> mLoadGroup;
 };