LibWeb: Make HTMLCollection faster when it only cares about children

Some of the live HTMLCollection only ever contain children of their root
node. When we know that's the case, we can avoid doing a full subtree
traversal of all descendants and only visit children.

This cuts the ECMA262 spec loading time by over 10 seconds. :^)

1 files changed, 1 insertions, 1 deletions

diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
index 1ebfe88206..aa81e2a713 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
@@ -244,7 +244,7 @@ static bool is_form_control(DOM::Element const& element)
 JS::NonnullGCPtr<DOM::HTMLCollection> HTMLFormElement::elements() const
 {
     if (!m_elements) {
-        m_elements = DOM::HTMLCollection::create(const_cast<HTMLFormElement&>(*this), [](Element const& element) {
+        m_elements = DOM::HTMLCollection::create(const_cast<HTMLFormElement&>(*this), DOM::HTMLCollection::Scope::Descendants, [](Element const& element) {
             return is_form_control(element);
         }).release_value_but_fixme_should_propagate_errors();
     }