When there are no more stylesheets schedule the recalc async

Source/core/dom/DocumentStyleSheetCollection.h

Index: Source/core/dom/DocumentStyleSheetCollection.h
diff --git a/Source/core/dom/DocumentStyleSheetCollection.h b/Source/core/dom/DocumentStyleSheetCollection.h
index 51997fa8e11097c8a34fbd4009f631c14395da60..337df669d0d0d4f01a0fa6deca18b8d268778632 100644
--- a/Source/core/dom/DocumentStyleSheetCollection.h
+++ b/Source/core/dom/DocumentStyleSheetCollection.h
@@ -28,6 +28,7 @@
 #ifndef DocumentStyleSheetCollection_h
 #define DocumentStyleSheetCollection_h
 
+#include "Document.h"
 #include <wtf/FastAllocBase.h>
 #include <wtf/ListHashSet.h>
 #include <wtf/RefPtr.h>
@@ -73,8 +74,7 @@ public:
 
     bool needsUpdateActiveStylesheetsOnStyleRecalc() const { return m_needsUpdateActiveStylesheetsOnStyleRecalc; }
 
-    enum UpdateFlag { FullUpdate, OptimizedUpdate };
-    bool updateActiveStyleSheets(UpdateFlag);
+    bool updateActiveStyleSheets(StyleResolverUpdateMode);
 
     String preferredStylesheetSetName() const { return m_preferredStylesheetSetName; }
     String selectedStylesheetSetName() const { return m_selectedStylesheetSetName; }
@@ -109,12 +109,9 @@ private:
     DocumentStyleSheetCollection(Document*);
 
     void collectActiveStyleSheets(Vector<RefPtr<StyleSheet> >&);
-    enum StyleResolverUpdateType {
-        Reconstruct,
-        Reset,
-        Additive
-    };
-    void analyzeStyleSheetChange(UpdateFlag, const Vector<RefPtr<CSSStyleSheet> >& newStylesheets, StyleResolverUpdateType&, bool& requiresFullStyleRecalc);
+
+    enum UpdateAction { Reconstruct, Reset, Append };
+    UpdateAction analyzeStyleSheetChange(StyleResolverUpdateMode, const Vector<RefPtr<CSSStyleSheet> >& newStylesheets, bool& requiresFullStyleRecalc);
 
     Document* m_document;