Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/dom/StyleElement.cpp

Index: third_party/WebKit/Source/core/dom/StyleElement.cpp
diff --git a/third_party/WebKit/Source/core/dom/StyleElement.cpp b/third_party/WebKit/Source/core/dom/StyleElement.cpp
index 269d5048f0d04d18b9afb8ec0efc4db4bf7d675f..b7ce53e46fe1bf4e13b25acf3614213ceacf7060 100644
--- a/third_party/WebKit/Source/core/dom/StyleElement.cpp
+++ b/third_party/WebKit/Source/core/dom/StyleElement.cpp
@@ -97,12 +97,11 @@ void StyleElement::removedFrom(Element* element, ContainerNode* insertionPoint)
         m_registeredAsCandidate = false;
     }
 
-    StyleSheet* removedSheet = m_sheet.get();
-
-    if (m_sheet)
+    if (m_sheet) {
         clearSheet(element);
-    if (removedSheet)
-        document.styleEngine().setNeedsActiveStyleUpdate(removedSheet, AnalyzedStyleUpdate);
+        if (element->inShadowIncludingDocument())
+            document.styleEngine().setNeedsActiveStyleUpdate(element->treeScope());
+    }
 }
 
 void StyleElement::clearDocumentData(Document& document, Element* element)