Bug 1800344 part 2: Fold nsSyncStreamListener::Create() into NS_NewSyncStreamListener(). r=necko-reviewers,kershaw

While we're at it: remove one layer of unnecessary error handling in
NS_NewSyncStreamListener, since it's clearer now that we'll be getting
infallible allocation.

Differential Revision: https://phabricator.services.mozilla.com/D161949

netwerk/base/nsNetUtil.cpp

@@ -1041,15 +1041,12 @@ nsresult NS_NewStreamLoader(
 
 nsresult NS_NewSyncStreamListener(nsIStreamListener** result,
                                   nsIInputStream** stream) {
-  nsCOMPtr<nsISyncStreamListener> listener = nsSyncStreamListener::Create();
-  if (listener) {
-    nsresult rv = listener->GetInputStream(stream);
-    if (NS_SUCCEEDED(rv)) {
-      listener.forget(result);
-    }
-    return rv;
+  nsCOMPtr<nsISyncStreamListener> listener = new nsSyncStreamListener();
+  nsresult rv = listener->GetInputStream(stream);
+  if (NS_SUCCEEDED(rv)) {
+    listener.forget(result);
   }
-  return NS_ERROR_FAILURE;
+  return rv;
 }
 
 nsresult NS_ImplementChannelOpen(nsIChannel* channel, nsIInputStream** result) {

netwerk/base/nsSyncStreamListener.cpp

@@ -12,21 +12,13 @@
 using namespace mozilla::net;
 
 nsSyncStreamListener::nsSyncStreamListener() {
+  MOZ_ASSERT(NS_IsMainThread());
   NS_NewPipe(getter_AddRefs(mPipeIn), getter_AddRefs(mPipeOut),
              mozilla::net::nsIOService::gDefaultSegmentSize,
              UINT32_MAX,  // no size limit
              false, false);
 }
 
-// NOTE: Next patch in this series will remove this.
-// static
-already_AddRefed<nsISyncStreamListener> nsSyncStreamListener::Create() {
-  MOZ_ASSERT(NS_IsMainThread());
-
-  RefPtr<nsSyncStreamListener> inst = new nsSyncStreamListener();
-  return inst.forget();
-}
-
 nsresult nsSyncStreamListener::WaitForData() {
   mKeepWaiting = true;
 

netwerk/base/nsSyncStreamListener.h

@@ -22,9 +22,10 @@ class nsSyncStreamListener final : public nsISyncStreamListener,
   NS_DECL_NSISYNCSTREAMLISTENER
   NS_DECL_NSIINPUTSTREAM
 
-  static already_AddRefed<nsISyncStreamListener> Create();
-
  private:
+  // Factory method:
+  friend nsresult NS_NewSyncStreamListener(nsIStreamListener** result,
+                                           nsIInputStream** stream);
   nsSyncStreamListener();
   ~nsSyncStreamListener() = default;