LibWeb: Don't prune whitespace nodes from layout tree

Various whitespace-related issues have been fixed, and support for the
different CSS white-space values is improved enough that I think we can
stop doing the hack where we just prune whitespace nodes from the tree
and actually let them show up.

This is a nice step forward for correctness with the slight downside of
cluttering up layout tree dumps with tons of whitespace text nodes.
But hey, that's the web we know & love. :^)

Fixes #4427.

Libraries/LibWeb/Layout/TextNode.cpp

@@ -57,21 +57,6 @@ static bool is_all_whitespace(const StringView& string)
     return true;
 }
 
-const String& TextNode::text_for_style(const CSS::StyleProperties& style) const
-{
-    static String one_space = " ";
-    if (is_all_whitespace(dom_node().data())) {
-        switch (style.white_space().value_or(CSS::WhiteSpace::Normal)) {
-        case CSS::WhiteSpace::Pre:
-        case CSS::WhiteSpace::PreWrap:
-            break;
-        default:
-            return one_space;
-        }
-    }
-    return dom_node().data();
-}
-
 void TextNode::paint_fragment(PaintContext& context, const LineBoxFragment& fragment, PaintPhase phase) const
 {
     auto& painter = context.painter();

Libraries/LibWeb/Layout/TextNode.h

@@ -40,7 +40,6 @@ public:
 
     const DOM::Text& dom_node() const { return static_cast<const DOM::Text&>(*Node::dom_node()); }
 
-    const String& text_for_style(const CSS::StyleProperties&) const;
     const String& text_for_rendering() const { return m_text_for_rendering; }
 
     virtual void paint_fragment(PaintContext&, const LineBoxFragment&, PaintPhase) const override;

Libraries/LibWeb/Layout/TreeBuilder.cpp

@@ -91,18 +91,10 @@ void TreeBuilder::create_layout_tree(DOM::Node& dom_node)
     if (dom_node.parent() && !dom_node.parent()->layout_node())
         return;
 
-    const CSS::StyleProperties* parent_style = nullptr;
-    if (!m_parent_stack.is_empty() && m_parent_stack.last()->dom_node() && m_parent_stack.last()->dom_node()->is_element())
-        parent_style = downcast<DOM::Element>(*m_parent_stack.last()->dom_node()).specified_css_values();
-
     auto layout_node = dom_node.create_layout_node();
     if (!layout_node)
         return;
 
-    // Discard empty whitespace nodes. This might not be ideal for correctness, but it does make the tree nicer.
-    if (is<TextNode>(*layout_node) && downcast<TextNode>(*layout_node).text_for_style(*parent_style) == " ")
-        return;
-
     if (!dom_node.parent()) {
         m_layout_root = layout_node;
     } else {