List marker pseudo elements.

Source/core/dom/Element.cpp

Index: Source/core/dom/Element.cpp
diff --git a/Source/core/dom/Element.cpp b/Source/core/dom/Element.cpp
index 73c0dd8b4d1f2937092fec0007f838441ba746bc..6a0f7bd484706020d7d182ce7f8058d9a39227b5 100644
--- a/Source/core/dom/Element.cpp
+++ b/Source/core/dom/Element.cpp
@@ -1344,12 +1344,33 @@ void Element::attach(const AttachContext& context)
     // from any of them.
     createPseudoElementIfNeeded(FIRST_LETTER);
 
+    // The marker has to come after the other content, including the BEFORE pseudo
+    // element so make sure we create it last.
+    if (RuntimeEnabledFeatures::listMarkerPseudoElementEnabled())
+        createPseudoElementIfNeeded(MARKER);
+
     if (hasRareData() && !renderer()) {
         if (ActiveAnimations* activeAnimations = elementRareData()->activeAnimations()) {
             activeAnimations->cssAnimations().cancel();
             activeAnimations->setAnimationStyleChange(false);
         }
     }
+
+    // If our parent has a marker pseudo element we need to inform them that we
+    // were attached as they may need to move the list marker.

[Julien - ping for review, 2014/12/05 19:44:03]

Move the list maker? Usually moving renderers is a bad idea as it may leave
pointers around (less and less the case but we have had a lot of issue with that
in the past)

[dsinclair, 2015/01/23 20:46:36]

Yea, it sucks but we still have to do it. It's possible we've inserted something
before the list marker, or removed something that effects the list marker. We
have to get the parent to look at the tree and see if everything is correct.

This worked before because we'd do it in layout. It was the same concept, in
that it would look at who the line boxes were and decide where the list marker
goes.

+    if (RuntimeEnabledFeatures::listMarkerPseudoElementEnabled() && parentNode() && parentNode()->isElementNode()) {
+        if (PseudoElement* pseudoElement = toElement(parentNode())->pseudoElement(MARKER)) {
+            bool neededRecalc = pseudoElement->needsStyleRecalc();
+            pseudoElement->setNeedsStyleRecalc(LocalStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::PseudoClass));
+
+            // If style recalc is currently executing, and we have already been recalc'd
+            // we need to tell our parent to do the recalc again because we need to
+            // re-initialize the first letter state. This can happen for things like
+            // RenderQuote where quotes processed later can effect things already styled.
+            if (document().inStyleRecalc() && !neededRecalc)
+                pseudoElement->recalcStyle(UpdatePseudoElements);
+        }
+    }
 }
 
 void Element::detach(const AttachContext& context)
@@ -1506,6 +1527,8 @@ void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling)
 
         updatePseudoElement(AFTER, change);
         updatePseudoElement(BACKDROP, change);
+        if (RuntimeEnabledFeatures::listMarkerPseudoElementEnabled())
+            updatePseudoElement(MARKER, change);
 
         // If our children have changed then we need to force the first-letter
         // checks as we don't know if they effected the first letter or not.
@@ -2513,7 +2536,8 @@ void Element::updatePseudoElement(PseudoId pseudoId, StyleRecalcChange change)
         // is false, otherwise we could continuously create and destroy PseudoElements
         // when RenderObject::isChildAllowed on our parent returns false for the
         // PseudoElement's renderer for each style recalc.
-        if (!renderer() || !pseudoElementRendererIsNeeded(renderer()->getCachedPseudoStyle(pseudoId)))
+        if (!renderer() ||
+            (!pseudoElementRendererIsNeeded(renderer()->getCachedPseudoStyle(pseudoId)) && (pseudoId == MARKER && renderer()->style()->display() != LIST_ITEM)))
             elementRareData()->setPseudoElement(pseudoId, nullptr);
     } else if (pseudoId == FIRST_LETTER && element && change >= UpdatePseudoElements && !FirstLetterPseudoElement::firstLetterTextRenderer(*element)) {
         // This can happen if we change to a float, for example. We need to cleanup the
@@ -2549,7 +2573,7 @@ bool Element::updateFirstLetter(Element* element)
 
 void Element::createPseudoElementIfNeeded(PseudoId pseudoId)
 {
-    if (isPseudoElement())
+    if (isPseudoElement() && (pseudoId != MARKER || isMarkerPseudoElement()))
         return;
 
     // Document::ensureStyleResolver is not inlined and shows up on profiles, avoid it here.
@@ -2557,9 +2581,9 @@ void Element::createPseudoElementIfNeeded(PseudoId pseudoId)
     RefPtrWillBeRawPtr<PseudoElement> element = engine->ensureResolver().createPseudoElementIfNeeded(*this, pseudoId);
     if (!element)
         return;
-
     if (pseudoId == BACKDROP)
         document().addToTopLayer(element.get(), this);
+
     element->insertedInto(this);
     element->attach();