diff --git a/mozilla/netwerk/base/public/nsIStreamLoader.idl b/mozilla/netwerk/base/public/nsIStreamLoader.idl
index 0eaeaff38ad..39799a188bd 100644
--- a/mozilla/netwerk/base/public/nsIStreamLoader.idl
+++ b/mozilla/netwerk/base/public/nsIStreamLoader.idl
@@ -66,6 +66,10 @@ interface nsIStreamLoader : nsISupports
               in nsIURI referrer,
               in unsigned long refererFlags);
 
+    void initWithChannel(in nsIChannel aChannel,
+              in nsIStreamLoaderObserver aObserver,
+              in nsISupports aContext);
+
     /**
      * Gets the number of bytes read so far.
      */
diff --git a/mozilla/netwerk/base/public/nsNetUtil.h b/mozilla/netwerk/base/public/nsNetUtil.h
index d8dd661f954..7394a66dcd3 100644
--- a/mozilla/netwerk/base/public/nsNetUtil.h
+++ b/mozilla/netwerk/base/public/nsNetUtil.h
@@ -434,6 +434,28 @@ NS_NewStreamLoader(nsIStreamLoader* *result,
     return rv;
 }
 
+inline nsresult
+NS_NewStreamLoader(nsIStreamLoader* *result,
+                   nsIChannel* channel,
+                   nsIStreamLoaderObserver* observer,
+                   nsISupports* context = nsnull)
+{
+    nsresult rv;
+    nsCOMPtr<nsIStreamLoader> loader;
+    static NS_DEFINE_CID(kStreamLoaderCID, NS_STREAMLOADER_CID);
+    rv = nsComponentManager::CreateInstance(kStreamLoaderCID,
+                                            nsnull,
+                                            NS_GET_IID(nsIStreamLoader),
+                                            getter_AddRefs(loader));
+    if (NS_FAILED(rv)) return rv;
+    rv = loader->InitWithChannel(channel, observer, context);
+                      
+    if (NS_FAILED(rv)) return rv;
+    *result = loader;
+    NS_ADDREF(*result);
+    return rv;
+}
+
 inline nsresult
 NS_NewRequestObserverProxy(nsIRequestObserver **aResult,
                            nsIRequestObserver *aObserver,
diff --git a/mozilla/netwerk/base/src/nsStreamLoader.cpp b/mozilla/netwerk/base/src/nsStreamLoader.cpp
index 51450b38ad9..bf8b0ac89c3 100644
--- a/mozilla/netwerk/base/src/nsStreamLoader.cpp
+++ b/mozilla/netwerk/base/src/nsStreamLoader.cpp
@@ -97,6 +97,39 @@ nsStreamLoader::Init(nsIURI* aURL,
   return rv;
 }
 
+NS_IMETHODIMP
+nsStreamLoader::InitWithChannel(nsIChannel* channel,
+                     nsIStreamLoaderObserver* observer,
+                     nsISupports* context)
+{
+  NS_ENSURE_ARG_POINTER(channel);
+  NS_ENSURE_ARG_POINTER(observer);
+
+  nsresult rv = channel->AsyncOpen(this, context);
+
+  if (NS_FAILED(rv) && observer) {
+    // don't callback synchronously as it puts the caller
+    // in a recursive situation and breaks the asynchronous
+    // semantics of nsIStreamLoader
+    nsresult rv2 = NS_OK;
+    nsCOMPtr<nsIProxyObjectManager> pIProxyObjectManager = 
+             do_GetService(kProxyObjectManagerCID, &rv2);
+    if (NS_FAILED(rv2)) return rv2;
+
+    nsCOMPtr<nsIStreamLoaderObserver> pObserver;
+    rv2 = pIProxyObjectManager->GetProxyForObject(NS_CURRENT_EVENTQ, 
+              NS_GET_IID(nsIStreamLoaderObserver), observer, 
+              PROXY_ASYNC | PROXY_ALWAYS, getter_AddRefs(pObserver));
+    if (NS_FAILED(rv2)) return rv2;
+
+    rv = pObserver->OnStreamComplete(this, context, rv, 0, nsnull);
+  }
+
+  mObserver = observer;
+  mContext  = context;
+  return rv;
+}
+
 NS_METHOD
 nsStreamLoader::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult)
 {