Bug 1440771 - Part 2: Use nsCOMPtr<nsIInputStream> directly in PCacheStreamControl, r=baku

MozReview-Commit-ID: 1Ab49lZtxTI

dom/cache/CacheStreamControlChild.cpp

@@ -125,9 +125,8 @@ CacheStreamControlChild::OpenStream(const nsID& aId, InputStreamResolver&& aReso
   RefPtr<CacheWorkerHolder> holder = GetWorkerHolder();
 
   SendOpenStream(aId)->Then(GetCurrentThreadSerialEventTarget(), __func__,
-  [aResolver, holder](const OptionalIPCStream& aOptionalStream) {
-    nsCOMPtr<nsIInputStream> stream = DeserializeIPCStream(aOptionalStream);
-    aResolver(Move(stream));
+  [aResolver, holder](const nsCOMPtr<nsIInputStream>& aOptionalStream) {
+    aResolver(nsCOMPtr<nsIInputStream>(aOptionalStream));
   }, [aResolver, holder](ResponseRejectReason aReason) {
     aResolver(nullptr);
   });

dom/cache/CacheStreamControlParent.cpp

@@ -127,20 +127,8 @@ CacheStreamControlParent::RecvOpenStream(const nsID& aStreamId,
 {
   NS_ASSERT_OWNINGTHREAD(CacheStreamControlParent);
 
-  // This is safe because:
-  //  1. We add ourself to the Manager as an operation Listener in OpenStream().
-  //  2. We remove ourself as a Listener from the Manager in ActorDestroy().
-  //  3. The Manager will not "complete" the operation if the Listener has
-  //     been removed.  This means the lambda will not be invoked.
-  //  4. The ActorDestroy() will also cause the child-side MozPromise for
-  //     this async returning method to be rejected.  So we don't have to
-  //     call the resolver in this case.
-  CacheStreamControlParent* self = this;
-
-  OpenStream(aStreamId, [self, aResolver](nsCOMPtr<nsIInputStream>&& aStream) {
-      AutoIPCStream stream;
-      Unused << stream.Serialize(aStream, self->Manager());
-      aResolver(stream.TakeOptionalValue());
+  OpenStream(aStreamId, [aResolver](nsCOMPtr<nsIInputStream>&& aStream) {
+      aResolver(aStream);
     });
 
   return IPC_OK();

dom/cache/PCacheStreamControl.ipdl

@@ -6,9 +6,9 @@ include protocol PBackground;
 include protocol PFileDescriptorSet;
 include protocol PChildToParentStream;
 include protocol PParentToChildStream;
-include IPCStream;
 
 using struct nsID from "nsID.h";
+using nsCOMPtr<nsIInputStream> from "mozilla/ipc/IPCStreamUtils.h";
 
 namespace mozilla {
 namespace dom {
@@ -19,7 +19,7 @@ protocol PCacheStreamControl
   manager PBackground;
 
 parent:
-  async OpenStream(nsID aStreamId) returns(OptionalIPCStream aStream);
+  async OpenStream(nsID aStreamId) returns(nsCOMPtr<nsIInputStream> aStream);
   async NoteClosed(nsID aStreamId);
 
 child: