LibWeb: Bring back cache of intrinsic sizes across layout runs

12c6ac78e2 with fixed mistake when cache
slot is copied instead of being referenced:
```cpp
auto cache =
    box.cached_intrinsic_sizes().min_content_height.ensure(width);
```
while it should've been:
```cpp
auto& cache =
    box.cached_intrinsic_sizes().min_content_height.ensure(width);
```

Libraries/LibWeb/DOM/CharacterData.cpp

@@ -147,7 +147,7 @@ WebIDL::ExceptionOr<void> CharacterData::replace_data(size_t offset, size_t coun
         static_cast<Layout::TextNode&>(*layout_node).invalidate_text_for_rendering();
 
         // We also need to relayout.
-        document().set_needs_layout(SetNeedsLayoutReason::CharacterDataReplaceData);
+        set_needs_layout_update(SetNeedsLayoutReason::CharacterDataReplaceData);
     }
 
     document().bump_character_data_version();

Libraries/LibWeb/DOM/Document.cpp

@@ -1211,20 +1211,6 @@ Optional<String> Document::encoding_parse_and_serialize_url(StringView url) cons
     return parsed_url->serialize();
 }
 
-void Document::set_needs_layout(SetNeedsLayoutReason reason)
-{
-    if (m_needs_layout)
-        return;
-    if constexpr (UPDATE_LAYOUT_DEBUG) {
-        // NOTE: We check some conditions here to avoid debug spam in documents that don't do layout.
-        auto navigable = this->navigable();
-        if (m_layout_root && navigable && navigable->active_document() == this)
-            dbgln_if(UPDATE_LAYOUT_DEBUG, "NEED LAYOUT {}", to_string(reason));
-    }
-    m_needs_layout = true;
-    schedule_layout_update();
-}
-
 void Document::invalidate_layout_tree(InvalidateLayoutTreeReason reason)
 {
     if (m_layout_root)
@@ -1299,7 +1285,7 @@ void Document::update_layout(UpdateLayoutReason reason)
 
     update_style();
 
-    if (!m_needs_layout && m_layout_root)
+    if (!m_needs_layout_update && m_layout_root)
         return;
 
     // NOTE: If this is a document hosting <template> contents, layout is unnecessary.
@@ -1329,11 +1315,16 @@ void Document::update_layout(UpdateLayoutReason reason)
         }
     }
 
-    // Assign each box that establishes a formatting context a list of absolutely positioned children it should take care of during layout
     m_layout_root->for_each_in_inclusive_subtree_of_type<Layout::Box>([&](auto& child) {
+        bool needs_layout_update = child.dom_node() && child.dom_node()->needs_layout_update();
+        if (needs_layout_update || child.is_anonymous()) {
+            child.reset_cached_intrinsic_sizes();
+        }
         child.clear_contained_abspos_children();
         return TraversalDecision::Continue;
     });
+
+    // Assign each box that establishes a formatting context a list of absolutely positioned children it should take care of during layout
     m_layout_root->for_each_in_inclusive_subtree([&](auto& child) {
         if (!child.is_absolutely_positioned())
             return TraversalDecision::Continue;
@@ -1396,7 +1387,10 @@ void Document::update_layout(UpdateLayoutReason reason)
         paintable()->recompute_selection_states(*range);
     }
 
-    m_needs_layout = false;
+    for_each_shadow_including_inclusive_descendant([](auto& node) {
+        node.reset_needs_layout_update();
+        return TraversalDecision::Continue;
+    });
 
     // Scrolling by zero offset will clamp scroll offset back to valid range if it was out of bounds
     // after the viewport size change.
@@ -1430,6 +1424,9 @@ void Document::update_layout(UpdateLayoutReason reason)
         }
         is_display_none = static_cast<Element&>(node).computed_properties()->display().is_none();
     }
+    if (node_invalidation.relayout) {
+        node.set_needs_layout_update(SetNeedsLayoutReason::StyleChange);
+    }
     if (node_invalidation.rebuild_layout_tree) {
         // We mark layout tree for rebuild starting from parent element to correctly invalidate
         // "display" property change to/from "contents" value.
@@ -1441,6 +1438,7 @@ void Document::update_layout(UpdateLayoutReason reason)
     }
     invalidation |= node_invalidation;
     node.set_needs_style_update(false);
+    invalidation |= node_invalidation;
 
     bool children_need_inherited_style_update = !invalidation.is_none();
     if (needs_full_style_update || node.child_needs_style_update() || children_need_inherited_style_update) {
@@ -1532,8 +1530,6 @@ void Document::update_style()
     auto invalidation = update_style_recursively(*this, style_computer(), false);
     if (!invalidation.is_none())
         invalidate_display_list();
-    if (invalidation.relayout)
-        set_needs_layout(SetNeedsLayoutReason::StyleChange);
     if (invalidation.rebuild_stacking_context_tree)
         invalidate_stacking_context_tree();
     m_needs_full_style_update = false;

Libraries/LibWeb/DOM/Document.h

@@ -50,26 +50,6 @@ enum class QuirksMode {
     Yes
 };
 
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
-    X(CharacterDataReplaceData)                       \
-    X(FinalizeACrossDocumentNavigation)               \
-    X(HTMLImageElementReactToChangesInTheEnvironment) \
-    X(HTMLImageElementUpdateTheImageData)             \
-    X(HTMLVideoElementSetVideoTrack)                  \
-    X(KeyframeEffect)                                 \
-    X(LayoutTreeUpdate)                               \
-    X(NavigableSetViewportSize)                       \
-    X(SVGImageElementFetchTheDocument)                \
-    X(StyleChange)
-
-enum class SetNeedsLayoutReason {
-#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
-    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
-#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
-};
-
-[[nodiscard]] StringView to_string(SetNeedsLayoutReason);
-
 #define ENUMERATE_INVALIDATE_LAYOUT_TREE_REASONS(X)       \
     X(DocumentAddAnElementToTheTopLayer)                  \
     X(DocumentRequestAnElementToBeRemovedFromTheTopLayer) \
@@ -358,8 +338,6 @@ public:
     void update_paint_and_hit_testing_properties_if_needed();
     void update_animated_style_if_needed();
 
-    void set_needs_layout(SetNeedsLayoutReason);
-
     void invalidate_layout_tree(InvalidateLayoutTreeReason);
     void invalidate_stacking_context_tree();
 
@@ -1076,8 +1054,6 @@ private:
     // Used by evaluate_media_queries_and_report_changes().
     Vector<WeakPtr<CSS::MediaQueryList>> m_media_query_lists;
 
-    bool m_needs_layout { false };
-
     bool m_needs_full_style_update { false };
     bool m_needs_full_layout_tree_update { false };
 

Libraries/LibWeb/DOM/Node.cpp

@@ -1405,7 +1405,7 @@ void Node::set_needs_layout_tree_update(bool value)
                 break;
             ancestor->m_child_needs_layout_tree_update = true;
         }
-        document().set_needs_layout(SetNeedsLayoutReason::LayoutTreeUpdate);
+        set_needs_layout_update(SetNeedsLayoutReason::LayoutTreeUpdate);
     }
 }
 
@@ -1425,6 +1425,27 @@ void Node::set_needs_style_update(bool value)
     }
 }
 
+void Node::set_needs_layout_update(SetNeedsLayoutReason reason)
+{
+    if (m_needs_layout_update)
+        return;
+
+    if constexpr (UPDATE_LAYOUT_DEBUG) {
+        // NOTE: We check some conditions here to avoid debug spam in documents that don't do layout.
+        auto navigable = this->navigable();
+        if (navigable && navigable->active_document() == this)
+            dbgln_if(UPDATE_LAYOUT_DEBUG, "NEED LAYOUT {}", to_string(reason));
+    }
+
+    m_needs_layout_update = true;
+
+    for (auto* ancestor = parent_or_shadow_host(); ancestor; ancestor = ancestor->parent_or_shadow_host()) {
+        if (ancestor->m_needs_layout_update)
+            break;
+        ancestor->m_needs_layout_update = true;
+    }
+}
+
 void Node::post_connection()
 {
 }

Libraries/LibWeb/DOM/Node.h

@@ -91,6 +91,26 @@ enum class StyleInvalidationReason {
 #undef __ENUMERATE_STYLE_INVALIDATION_REASON
 };
 
+#define ENUMERATE_SET_NEEDS_LAYOUT_REASONS(X)         \
+    X(CharacterDataReplaceData)                       \
+    X(FinalizeACrossDocumentNavigation)               \
+    X(HTMLImageElementReactToChangesInTheEnvironment) \
+    X(HTMLImageElementUpdateTheImageData)             \
+    X(HTMLVideoElementSetVideoTrack)                  \
+    X(KeyframeEffect)                                 \
+    X(LayoutTreeUpdate)                               \
+    X(NavigableSetViewportSize)                       \
+    X(SVGImageElementFetchTheDocument)                \
+    X(StyleChange)
+
+enum class SetNeedsLayoutReason {
+#define ENUMERATE_SET_NEEDS_LAYOUT_REASON(e) e,
+    ENUMERATE_SET_NEEDS_LAYOUT_REASONS(ENUMERATE_SET_NEEDS_LAYOUT_REASON)
+#undef ENUMERATE_SET_NEEDS_LAYOUT_REASON
+};
+
+[[nodiscard]] StringView to_string(SetNeedsLayoutReason);
+
 class Node : public EventTarget
     , public TreeNode<Node> {
     WEB_PLATFORM_OBJECT(Node, EventTarget);
@@ -291,6 +311,10 @@ public:
     void set_needs_style_update(bool);
     void set_needs_style_update_internal(bool) { m_needs_style_update = true; }
 
+    bool needs_layout_update() const { return m_needs_layout_update; }
+    void set_needs_layout_update(SetNeedsLayoutReason);
+    void reset_needs_layout_update() { m_needs_layout_update = false; }
+
     bool child_needs_style_update() const { return m_child_needs_style_update; }
     void set_child_needs_style_update(bool b) { m_child_needs_style_update = b; }
 
@@ -528,6 +552,8 @@ protected:
     bool m_child_needs_style_update { false };
     bool m_entire_subtree_needs_style_update { false };
 
+    bool m_needs_layout_update { false };
+
     UniqueNodeID m_unique_id;
 
     // https://dom.spec.whatwg.org/#registered-observer-list