List marker pseudo elements.

Source/core/layout/LayoutListMarker.cpp

Index: Source/core/layout/LayoutListMarker.cpp
diff --git a/Source/core/layout/LayoutListMarker.cpp b/Source/core/layout/LayoutListMarker.cpp
index 01a02be83af6053ee2a2df3d0b530a56b31ed374..59ecd761379bc5d34ebcc180b30997ca5728473c 100644
--- a/Source/core/layout/LayoutListMarker.cpp
+++ b/Source/core/layout/LayoutListMarker.cpp
@@ -25,6 +25,7 @@
 #include "config.h"
 #include "core/layout/LayoutListMarker.h"
 
+#include "core/dom/MarkerPseudoElement.h"
 #include "core/fetch/ImageResource.h"
 #include "core/layout/LayoutAnalyzer.h"
 #include "core/layout/LayoutListItem.h"
@@ -1048,6 +1049,15 @@ String listMarkerText(EListStyleType type, int value)
     return "";
 }
 
+LayoutListMarker::LayoutListMarker(Element* node, LayoutListItem* item)
+    : LayoutBox(node)
+    , m_listItem(item)
+{
+    // init LayoutObject attributes
+    setInline(true); // our object is Inline
+    setReplaced(true); // pretend to be replaced

[esprehn, 2015/04/20 16:04:08]

Link to the spec? 

[dsinclair, 2015/04/21 20:23:10]

This is from the constructor below. I needed to add a second constructor in
order to provide the node pointer for the LayoutBox call. I'm not sure why these
are set on the ListMarker.

+}
+
 LayoutListMarker::LayoutListMarker(LayoutListItem* item)
     : LayoutBox(0)
     , m_listItem(item)
@@ -1071,9 +1081,9 @@ void LayoutListMarker::destroy()
 LayoutListMarker* LayoutListMarker::createAnonymous(LayoutListItem* item)
 {
     Document& document = item->document();
-    LayoutListMarker* renderer = new LayoutListMarker(item);
-    renderer->setDocumentForAnonymous(&document);
-    return renderer;
+    LayoutListMarker* layoutObject = new LayoutListMarker(item);
+    layoutObject->setDocumentForAnonymous(&document);
+    return layoutObject;
 }
 
 void LayoutListMarker::styleWillChange(StyleDifference diff, const ComputedStyle& newStyle)
@@ -1088,6 +1098,13 @@ void LayoutListMarker::styleDidChange(StyleDifference diff, const ComputedStyle*
 {
     LayoutBox::styleDidChange(diff, oldStyle);
 
+    if (RuntimeEnabledFeatures::listMarkerPseudoElementEnabled()) {
+        updateMarginsAndContent();
+
+        if (isInside())
+            node()->parentElement()->layoutObject()->containingBlock()->updateLogicalWidth();

[esprehn, 2015/04/20 16:04:08]

You can't update logical widths from inside a style change (especially not on
your containingBlock), more things might change during style recalc or in its
descendants still. All you can do is mark yourself dirty.

[dsinclair, 2015/04/21 20:23:10]

Done. If I remove the updateMarginsAndContent() things no longer work, is that
one OK to do inside style did change?

[esprehn, 2015/04/22 07:45:44]

You should do this in layout, we already do for the isImage() case, just move
that out of the if statement.

+    }
+
     if (m_image != style()->listStyleImage()) {
         if (m_image)
             m_image->removeClient(this);
@@ -1636,16 +1653,8 @@ LayoutRect LayoutListMarker::selectionRectForPaintInvalidation(const LayoutBoxMo
 
 void LayoutListMarker::listItemStyleDidChange()
 {
-    RefPtr<ComputedStyle> newStyle = ComputedStyle::create();
-    // The marker always inherits from the list item, regardless of where it might end
-    // up (e.g., in some deeply nested line box). See CSS3 spec.
-    newStyle->inheritFrom(m_listItem->styleRef());
-    if (style()) {
-        // Reuse the current margins. Otherwise resetting the margins to initial values
-        // would trigger unnecessary layout.
-        newStyle->setMarginStart(style()->marginStart());
-        newStyle->setMarginEnd(style()->marginRight());
-    }
+    ASSERT(!RuntimeEnabledFeatures::listMarkerPseudoElementEnabled());
+    RefPtr<ComputedStyle> newStyle = MarkerPseudoElement::styleForListMarkerLayoutObject(*m_listItem, style());
     setStyle(newStyle.release());
 }