Rework list marker spacing for better web compatibility.

third_party/WebKit/Source/core/layout/LayoutListItem.cpp

 /**
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 36 matching lines @@
     setInline(false);
 
     setConsumesSubtreeChangeNotification();
     registerSubtreeChangeListenerOnDescendants(true);
 }
 
 void LayoutListItem::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
 {
     LayoutBlockFlow::styleDidChange(diff, oldStyle);
 
+    StyleImage* currentImage = style()->listStyleImage();
     if (style()->listStyleType() != NoneListStyle
-        || (style()->listStyleImage() && !style()->listStyleImage()->errorOccurred())) {
+        || (currentImage && !currentImage->errorOccurred())) {

[wkorman, 2015/10/14 01:55:30]

codereview UI isn't showing your comment in-line here for some reason -- re:
whether this can cause list style image to change, I believe yes, which would be
handled by the bit below (line 69+), but I may be missing something, let me
know.

         if (!m_marker)
             m_marker = LayoutListMarker::createAnonymous(this);
         m_marker->listItemStyleDidChange();
         notifyOfSubtreeChange();

[eae, 2015/10/12 06:02:01]

Can this cause style()->listStyleImage() to change? If so we need to handle
that, if not please add an assert.

     } else if (m_marker) {
         m_marker->destroy();
         m_marker = nullptr;
     }
 
     StyleImage* oldImage = oldStyle ? oldStyle->listStyleImage() : nullptr;
-    if (oldImage != style()->listStyleImage()) {
+    if (oldImage != currentImage) {
         if (oldImage)
             oldImage->removeClient(this);
-        if (style()->listStyleImage())
-            style()->listStyleImage()->addClient(this);
+        if (currentImage)
+            currentImage->addClient(this);
     }
 }
 
 void LayoutListItem::willBeDestroyed()
 {
     if (m_marker) {
         m_marker->destroy();
         m_marker = nullptr;
     }
 
@@ skipping 128 matching lines @@
 
     return itemCount;
 }
 
 inline int LayoutListItem::calcValue() const
 {
     if (m_hasExplicitValue)
         return m_explicitValue;
 
     Node* list = enclosingList(this);
-    HTMLOListElement* oListElement = isHTMLOListElement(list) ? toHTMLOListElement(list) : 0;
+    HTMLOListElement* oListElement = isHTMLOListElement(list) ? toHTMLOListElement(list) : nullptr;
     int valueStep = 1;
     if (oListElement && oListElement->isReversed())
         valueStep = -1;
 
     // FIXME: This recurses to a possible depth of the length of the list.
     // That's not good -- we need to change this to an iterative algorithm.
     if (LayoutListItem* previousItem = previousListItem(list, this))
         return previousItem->value() + valueStep;
 
     if (oListElement)
@@ skipping 275 matching lines @@
             // assume that all the following ones have too.
             // This gives us the opportunity to stop here and avoid
             // marking the same nodes again.
             break;
         }
         item->updateValue();
     }
 }
 
 } // namespace blink