Bug 1496147 - part 0: Use alias template to define StrongPtrForMember<T>. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D64056

--HG--
extra : moz-landing-system : lando

dom/bindings/BindingUtils.h

@@ -3066,10 +3066,8 @@ template <class T, template <typename> class SmartPtr, class S>
 inline void StrongOrRawPtr(SmartPtr<S>&& aPtr) = delete;
 
 template <class T>
-struct StrongPtrForMember {
-  typedef typename Conditional<IsRefcounted<T>::value, RefPtr<T>,
-                               nsAutoPtr<T>>::Type Type;
-};
+using StrongPtrForMember =
+    typename Conditional<IsRefcounted<T>::value, RefPtr<T>, nsAutoPtr<T>>::Type;
 
 namespace binding_detail {
 inline JSObject* GetHackedNamespaceProtoObject(JSContext* aCx) {

dom/bindings/Codegen.py

@@ -7314,7 +7314,7 @@ def getRetvalDeclarationForType(returnType, descriptorProvider,
             typeName = "Promise"
         if isMember:
             conversion = None
-            result = CGGeneric("StrongPtrForMember<%s>::Type" % typeName)
+            result = CGGeneric("StrongPtrForMember<%s>" % typeName)
         else:
             conversion = CGGeneric("StrongOrRawPtr<%s>" % typeName)
             result = CGGeneric("auto")