Use LocalStyleChange for insertion point inheritance propagation.

third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 104 matching lines @@
 void InsertionPoint::detachLayoutTree(const AttachContext& context)
 {
     for (size_t i = 0; i < m_distributedNodes.size(); ++i)
         m_distributedNodes.at(i)->lazyReattachIfAttached();
 
     HTMLElement::detachLayoutTree(context);
 }
 
 void InsertionPoint::willRecalcStyle(StyleRecalcChange change)
 {
-    if (change < IndependentInherit && getStyleChangeType() < SubtreeStyleChange)
+    StyleChangeType styleChangeType = NoStyleChange;
+
+    if (change > Inherit || getStyleChangeType() > LocalStyleChange)
+        styleChangeType = SubtreeStyleChange;
+    else if (change > NoInherit)
+        styleChangeType = LocalStyleChange;
+    else
         return;
+
     for (size_t i = 0; i < m_distributedNodes.size(); ++i)
-        m_distributedNodes.at(i)->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::PropagateInheritChangeToDistributedNodes));
+        m_distributedNodes.at(i)->setNeedsStyleRecalc(styleChangeType, StyleChangeReasonForTracing::create(StyleChangeReason::PropagateInheritChangeToDistributedNodes));
 }
 
 bool InsertionPoint::canBeActive() const
 {
     ShadowRoot* shadowRoot = containingShadowRoot();
     if (!shadowRoot)
         return false;
     if (shadowRoot->isV1())
         return false;
     return !Traversal<InsertionPoint>::firstAncestor(*this);
@@ skipping 146 matching lines @@
         if (!insertionPoints)
             return;
         for (size_t i = 0; i < insertionPoints->size(); ++i)
             results.append(insertionPoints->at(i).get());
         DCHECK_NE(current, insertionPoints->last().get());
         current = insertionPoints->last().get();
     }
 }
 
 } // namespace blink