Support display: contents for elements, first-line and first-letter pseudos.

third_party/WebKit/Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc.
  * All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
@@ skipping 1509 matching lines @@
     return parent->locateNamespacePrefix(namespaceToLocate);
 
   return nullAtom;
 }
 
 const AtomicString Element::imageSourceURL() const {
   return getAttribute(srcAttr);
 }
 
 bool Element::layoutObjectIsNeeded(const ComputedStyle& style) {
-  return style.display() != EDisplay::None;
+  return style.display() != EDisplay::None &&
+         style.display() != EDisplay::Contents;
 }
 
 LayoutObject* Element::createLayoutObject(const ComputedStyle& style) {
   return LayoutObject::createObject(this, style);
 }
 
 Node::InsertionNotificationRequest Element::insertedInto(
     ContainerNode* insertionPoint) {
   // need to do superclass processing first so isConnected() is true
   // by the time we reach updateId
@@ skipping 117 matching lines @@
 void Element::attachLayoutTree(const AttachContext& context) {
   DCHECK(document().inStyleRecalc());
 
   // We've already been through detach when doing an attach, but we might
   // need to clear any state that's been added since then.
   if (hasRareData() && getStyleChangeType() == NeedsReattachStyleChange) {
     ElementRareData* data = elementRareData();
     data->clearComputedStyle();
   }
 
-  if (!isSlotOrActiveInsertionPoint())
-    LayoutTreeBuilderForElement(*this, context.resolvedStyle)
-        .createLayoutObjectIfNeeded();
+  if (!isSlotOrActiveInsertionPoint()) {
+    LayoutTreeBuilderForElement builder(*this, context.resolvedStyle);
+    builder.createLayoutObjectIfNeeded();
+
+    // Persist the resolved style if we got to the point we needed to compute
+    // the style, and it was a display: contents style, since we need it for our
+    // children.
+    if (ComputedStyle* style = builder.resolvedStyle()) {
+      if (style->display() == EDisplay::Contents) {
+        DCHECK(!layoutObject());
+        storeDisplayContentsStyle(*style);
+      }
+    }
+  }
 
   addCallbackSelectors();
 
   if (hasRareData() && !layoutObject()) {
     if (ElementAnimations* elementAnimations =
             elementRareData()->elementAnimations()) {
       elementAnimations->cssAnimations().cancel();
       elementAnimations->setAnimationStyleChange(false);
     }
   }
@@ skipping 315 matching lines @@
   // flag - so needsReattachLayoutTree() should always be true.
   DCHECK(parentNode());
   DCHECK(parentNode()->childNeedsReattachLayoutTree());
   DCHECK(needsReattachLayoutTree());
   reattachLayoutTree(reattachContext);
   // Since needsReattachLayoutTree() is always true we go into
   // reattachLayoutTree() which reattaches all the descendant
   // sub-trees. At this point no child should need reattaching.
   DCHECK(!childNeedsReattachLayoutTree());
 
-  if (layoutObjectWillChange || layoutObject()) {
+  if (layoutObjectWillChange || layoutObject() || displayContentsStyle()) {
     // nextTextSibling is passed on to recalcStyle from recalcDescendantStyles
     // we can either traverse the current subtree from this node onwards
     // or store it.
     // The choice is between increased time and increased memory complexity.
     reattachWhitespaceSiblingsIfNeeded(nextTextSibling());
     return Reattach;
   }
   return ReattachNoLayoutObject;
 }
 
@@ skipping 1109 matching lines @@
 
   RefPtr<ComputedStyle> result =
       document().ensureStyleResolver().pseudoStyleForElement(
           this, PseudoStyleRequest(pseudoElementSpecifier,
                                    PseudoStyleRequest::ForComputedStyle),
           elementStyle);
   DCHECK(result);
   return elementStyle->addCachedPseudoStyle(result.release());
 }
 
+const ComputedStyle* Element::displayContentsStyle() const {
+  if (layoutObject() || !hasRareData())
+    return nullptr;
+
+  ComputedStyle* style = elementRareData()->computedStyle();
+  if (!style || style->display() != EDisplay::Contents)
+    return nullptr;
+
+  return style;
+}
+
+void Element::storeDisplayContentsStyle(ComputedStyle& style) {
+  DCHECK_EQ(style.display(), EDisplay::Contents);
+  ensureElementRareData().setComputedStyle(&style);
+}
+
 AtomicString Element::computeInheritedLanguage() const {
   const Node* n = this;
   AtomicString value;
   // The language property is inherited, so we iterate over the parents to find
   // the first language.
   do {
     if (n->isElementNode()) {
       if (const ElementData* elementData = toElement(n)->elementData()) {
         AttributeCollection attributes = elementData->attributes();
         // Spec: xml:lang takes precedence -- http://www.w3.org/TR/xhtml1/#C_7
@@ skipping 948 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (hasRareData()) {
     visitor->traceWrappers(elementRareData());
   }
   ContainerNode::traceWrappers(visitor);
 }
 
 }  // namespace blink