Bug 2017797 - Part 2: Don't require bindings header for IS_INSTANCE_OF, r=smaug

The implementaion of IS_INSTANCE_OF previously specified the true native type T to UnwrapObjectInternal. This is unnecessary, as it is not part of the actual "IsInstanceOf" check, and is only used for a static cast (which is then discarded). This patch changes the passed-in type to be `void`. This change should have no runtime effect (the value was assigned into a void* immediately anyways), but avoids requiring callers which use IS_INSTANCE_OF to import the relevant bindings headers. Differential Revision: https://phabricator.services.mozilla.com/D284522

Author: mystor

dom/bindings/BindingUtils.h

@@ -172,10 +172,8 @@ inline bool IsDOMObject(JSObject* obj) { return IsDOMClass(JS::GetClass(obj)); }
  obj, value, cx)
 
 // Test whether the given object is an instance of the given interface.
-#define IS_INSTANCE_OF(Interface, obj) \
- mozilla::dom::IsInstanceOf<mozilla::dom::prototypes::id::Interface, \
- mozilla::dom::Interface##_Binding::NativeType>( \
- obj)
+#define IS_INSTANCE_OF(Interface, obj) \
+ mozilla::dom::IsInstanceOf<mozilla::dom::prototypes::id::Interface>(obj)
 
 // Unwrap the given non-wrapper object. This can be used with any obj that
 // converts to JSObject*; as long as that JSObject* is live the return value
@@ -422,11 +420,11 @@ MOZ_ALWAYS_INLINE nsresult UnwrapObjectWithCrossOriginAsserts(V&& obj,
 }
 } // namespace binding_detail
 
-template <prototypes::ID PrototypeID, class T>
+template <prototypes::ID PrototypeID>
 MOZ_ALWAYS_INLINE bool IsInstanceOf(JSObject* obj) {
  AssertStaticUnwrapOK<PrototypeID>();
  void* ignored;
- nsresult unwrapped = binding_detail::UnwrapObjectInternal<T, true>(
+ nsresult unwrapped = binding_detail::UnwrapObjectInternal<void, true>(
  obj, ignored, PrototypeID, PrototypeTraits<PrototypeID>::Depth, nullptr);
  return NS_SUCCEEDED(unwrapped);
 }