Make setNeedsActiveStyleUpdate mark treescope dirty only.

third_party/WebKit/Source/core/dom/StyleEngine.h

Index: third_party/WebKit/Source/core/dom/StyleEngine.h
diff --git a/third_party/WebKit/Source/core/dom/StyleEngine.h b/third_party/WebKit/Source/core/dom/StyleEngine.h
index 0671127265fba7fc7f37d1a4b4acf8e8d9fd5da7..9f29506644bb36c088b56ee81e8f4018895a98f8 100644
--- a/third_party/WebKit/Source/core/dom/StyleEngine.h
+++ b/third_party/WebKit/Source/core/dom/StyleEngine.h
@@ -61,7 +61,6 @@ class RuleFeatureSet;
 class ShadowTreeStyleSheetCollection;
 class StyleRuleFontFace;
 class StyleRuleUsageTracker;
-class StyleSheet;
 class StyleSheetContents;
 class ViewportStyleResolver;
 
@@ -103,7 +102,7 @@ class CORE_EXPORT StyleEngine final
   const HeapVector<Member<CSSStyleSheet>> activeStyleSheetsForInspector() const;
 
   bool needsActiveStyleUpdate() const;
-  void setNeedsActiveStyleUpdate(StyleSheet*, StyleResolverUpdateMode);
+  void setNeedsActiveStyleUpdate(TreeScope&);
   void addStyleSheetCandidateNode(Node&);
   void removeStyleSheetCandidateNode(Node&, ContainerNode& insertionPoint);
   void modifiedStyleSheetCandidateNode(Node&);