Current work-in-progress crbug.com/567021

third_party/WebKit/Source/core/html/HTMLLinkElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp b/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
index f8ce12194284324ffa41a7c1d1e18dbf57e7ccb1..746d39840603a7113a7b7394a440b9757aeb2af3 100644
--- a/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLLinkElement.cpp
@@ -305,13 +305,8 @@ void HTMLLinkElement::removedFrom(ContainerNode* insertionPoint)
         return;
     }
     document().styleEngine().removeStyleSheetCandidateNode(this);
-
-    StyleSheet* removedSheet = sheet();
-
     if (m_link)
         m_link->ownerRemoved();
-
-    document().styleEngine().setNeedsActiveStyleUpdate(removedSheet, FullStyleUpdate);
 }
 
 void HTMLLinkElement::finishParsingChildren()
@@ -761,11 +756,14 @@ void LinkStyle::process()
             removePendingSheet();
             notifyLoadedSheetAndAllCriticalSubresources(Node::ErrorOccurredLoadingSubresource);
         }
+        String title = m_owner->title();
+        if (!title.isEmpty() && !m_owner->isAlternate() && m_disabledState != EnabledViaScript)
+            document().styleEngine().setPreferredStylesheetSetNameIfNotSet(title);
     } else if (m_sheet) {
         // we no longer contain a stylesheet, e.g. perhaps rel or type was changed
-        StyleSheet* removedSheet = m_sheet.get();
         clearSheet();
-        document().styleEngine().setNeedsActiveStyleUpdate(removedSheet, FullStyleUpdate);
+        if (m_owner->inShadowIncludingDocument())
+            document().styleEngine().setNeedsActiveStyleUpdate(m_owner->treeScope());
     }
 }