Rename default -> initial style and use singletons.

Source/core/css/resolver/StyleResolver.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 97 matching lines @@
     PassRefPtr<LayoutStyle> styleForElement(Element*, LayoutStyle* parentStyle = 0, StyleSharingBehavior = AllowStyleSharing,
         RuleMatchingBehavior = MatchAllRules);
 
     PassRefPtr<LayoutStyle> styleForKeyframe(Element&, const LayoutStyle&, LayoutStyle* parentStyle, const StyleRuleKeyframe*, const AtomicString& animationName);
     static PassRefPtrWillBeRawPtr<AnimatableValue> createAnimatableValueSnapshot(Element&, CSSPropertyID, CSSValue*);
     static PassRefPtrWillBeRawPtr<AnimatableValue> createAnimatableValueSnapshot(StyleResolverState&, CSSPropertyID, CSSValue*);
 
     PassRefPtr<LayoutStyle> pseudoStyleForElement(Element*, const PseudoStyleRequest&, LayoutStyle* parentStyle);
 
     PassRefPtr<LayoutStyle> styleForPage(int pageIndex);
-    PassRefPtr<LayoutStyle> defaultStyleForElement();
     PassRefPtr<LayoutStyle> styleForText(Text*);
 
     static PassRefPtr<LayoutStyle> styleForDocument(Document&);
 
     // FIXME: It could be better to call appendAuthorStyleSheets() directly after we factor StyleResolver further.
     // https://bugs.webkit.org/show_bug.cgi?id=108890
     void appendAuthorStyleSheets(const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>&);
     void resetAuthorStyle(TreeScope&);
     void finishAppendAuthorStyleSheets();
 
@@ skipping 69 matching lines @@
     void increaseStyleSharingDepth() { ++m_styleSharingDepth; }
     void decreaseStyleSharingDepth() { --m_styleSharingDepth; }
 
     PassRefPtrWillBeRawPtr<PseudoElement> createPseudoElementIfNeeded(Element& parent, PseudoId);
 
     DECLARE_TRACE();
 
     void addTreeBoundaryCrossingScope(ContainerNode& scope);
 
 private:
+    PassRefPtr<LayoutStyle> initialStyleForElement();
+
     void initWatchedSelectorRules(const WillBeHeapVector<RefPtrWillBeMember<StyleRule>>& watchedSelectors);
 
     // FIXME: This should probably go away, folded into FontBuilder.
     void updateFont(StyleResolverState&);
 
     static AuthorStyleInfo authorStyleInfo(StyleResolverState&);
 
     void loadPendingResources(StyleResolverState&);
     void adjustLayoutStyle(StyleResolverState&, Element*);
 
@@ skipping 74 matching lines @@
     OwnPtr<StyleResolverStats> m_styleResolverStatsTotals;
     unsigned m_styleResolverStatsSequence;
 
     // Use only for Internals::updateStyleAndReturnAffectedElementCount.
     unsigned m_accessCount;
 };
 
 } // namespace blink
 
 #endif // StyleResolver_h