Avoid unnecessary invalidation scheduling.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 200 matching lines @@
         return m_documentStyleSheetCollection.get();
     }
 
     DocumentStyleSheetCollection* documentStyleSheetCollection()
     {
         return m_documentStyleSheetCollection.get();
     }
 
     void updateActiveStyleSheetsInShadow(StyleResolverUpdateMode, TreeScope*, UnorderedTreeScopeSet& treeScopesRemoved);
 
+    bool shouldSkipInvalidationFor(const Element&) const;
+
     RawPtrWillBeMember<Document> m_document;
     bool m_isMaster;
 
     // Track the number of currently loading top-level stylesheets needed for layout.
     // Sheets loaded using the @import directive are not included in this count.
     // We use this count of pending sheets to detect when we can begin attaching
     // elements and when it is safe to execute scripts.
     int m_pendingStylesheets;
 
     WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>> m_injectedAuthorStyleSheets;
@@ skipping 23 matching lines @@
 
     RefPtrWillBeMember<CSSFontSelector> m_fontSelector;
 
     WillBeHeapHashMap<AtomicString, RawPtrWillBeMember<StyleSheetContents>> m_textToSheetCache;
     WillBeHeapHashMap<RawPtrWillBeMember<StyleSheetContents>, AtomicString> m_sheetToTextCache;
 };
 
 }
 
 #endif