Bug 1478850 - FetchStreamReader must call HoldJSObject()/DropJSObjects, r=smaug

dom/fetch/FetchStreamReader.cpp

@@ -99,11 +99,15 @@ FetchStreamReader::FetchStreamReader(nsIGlobalObject* aGlobal)
   , mStreamClosed(false)
 {
   MOZ_ASSERT(aGlobal);
+
+  mozilla::HoldJSObjects(this);
 }
 
 FetchStreamReader::~FetchStreamReader()
 {
   CloseAndRelease(nullptr, NS_BASE_STREAM_CLOSED);
+
+  mozilla::DropJSObjects(this);
 }
 
 // If a context is provided, an attempt will be made to cancel the reader.  The