Fix missing distribution recalc in quirks mode and Shadow DOM v0.

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 1469 matching lines @@
       if (!new_id.IsEmpty() && feature_set.HasSelectorForId(new_id))
         return true;
     }
   }
 
   if (name == HTMLNames::classAttr) {
     const AtomicString& new_class_string = new_value;
     if (ClassStringHasClassName(new_class_string) ==
         ClassStringContent::kHasClasses) {
       const SpaceSplitString& old_classes = GetElementData()->ClassNames();
-      const SpaceSplitString new_classes(
-          new_class_string, GetDocument().InQuirksMode()
-                                ? SpaceSplitString::kShouldFoldCase
-                                : SpaceSplitString::kShouldNotFoldCase);
+      const SpaceSplitString new_classes(GetDocument().InQuirksMode()
+                                             ? new_class_string.LowerASCII()
+                                             : new_class_string,
+                                         SpaceSplitString::kShouldNotFoldCase);
       if (feature_set.CheckSelectorsForClassChange(old_classes, new_classes))
         return true;
     } else {
       const SpaceSplitString& old_classes = GetElementData()->ClassNames();
       if (feature_set.CheckSelectorsForClassChange(old_classes))
         return true;
     }
   }
 
   return feature_set.HasSelectorForAttribute(name.LocalName());
@@ skipping 2844 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(Element) {
   if (HasRareData()) {
     visitor->TraceWrappers(GetElementRareData());
   }
   ContainerNode::TraceWrappers(visitor);
 }
 
 }  // namespace blink