Bug 1798461 - Allow LastRelease definition in classes which inherit from WritableStream; r=saschanaz

Differential Revision: https://phabricator.services.mozilla.com/D160896

dom/streams/WritableStream.cpp

@@ -42,7 +42,8 @@ NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_WITH_JS_MEMBERS(
     (mPendingAbortRequestReason, mStoredError))
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(WritableStream)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(WritableStream)
+NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(WritableStream,
+                                                   LastRelease())
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(WritableStream)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)

dom/streams/WritableStream.h

@@ -36,6 +36,8 @@ class WritableStream : public nsISupports, public nsWrapperCache {
  protected:
   virtual ~WritableStream();
 
+  virtual void LastRelease() {}
+
  public:
   explicit WritableStream(const GlobalObject& aGlobal);
   explicit WritableStream(nsIGlobalObject* aGlobal);