clang/win: Work around in-class initializer bug.

Source/core/css/resolver/MatchResult.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.
  * Copyright (C) 2013 Google 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.
  *
@@ skipping 69 matching lines @@
     bool isEmpty() const { return begin() == end(); }
 
 private:
     MatchedPropertiesVector::const_iterator m_begin;
     MatchedPropertiesVector::const_iterator m_end;
 };
 
 class CORE_EXPORT MatchResult {
     STACK_ALLOCATED();
 public:
+    MatchResult();
+
     void addMatchedProperties(const StylePropertySet* properties, unsigned linkMatchType = CSSSelector::MatchAll, PropertyWhitelistType = PropertyWhitelistNone);
     bool hasMatchedProperties() const { return m_matchedProperties.size(); }
 
     void finishAddingUARules();
     void finishAddingAuthorRulesForTreeScope();
 
     void setIsCacheable(bool cacheable) { m_isCacheable = cacheable; }
     bool isCacheable() const { return m_isCacheable; }
 
     MatchedPropertiesRange allRules() const { return MatchedPropertiesRange(m_matchedProperties.begin(), m_matchedProperties.end()); }
@@ skipping 60 matching lines @@
 }
 
 inline bool operator!=(const MatchedProperties& a, const MatchedProperties& b)
 {
     return !(a == b);
 }
 
 } // namespace blink
 
 #endif // MatchResult_h