StyleResolver should update RuleSets lazily.

Source/core/css/FontFaceSet.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 405 matching lines @@
     // Now map the font property longhands into the style.
     CSSPropertyValue properties[] = {
         CSSPropertyValue(CSSPropertyFontFamily, *parsedStyle),
         CSSPropertyValue(CSSPropertyFontStyle, *parsedStyle),
         CSSPropertyValue(CSSPropertyFontVariant, *parsedStyle),
         CSSPropertyValue(CSSPropertyFontWeight, *parsedStyle),
         CSSPropertyValue(CSSPropertyFontSize, *parsedStyle),
         CSSPropertyValue(CSSPropertyLineHeight, *parsedStyle),
     };
     StyleResolver* styleResolver = document()->styleResolver();
+    appendPendingStyleSheetsIfNeeded(styleResolver);
     styleResolver->applyPropertiesToStyle(properties, WTF_ARRAY_LENGTH(properties), style.get());
 
     font = style->font();
     font.update(styleResolver->fontSelector());
     return true;
 }
 
 void FontFaceSet::FontLoadHistogram::record()
 {
     if (m_recorded)
@@ skipping 19 matching lines @@
 }
 
 void FontFaceSet::didLayout(Document* document)
 {
     if (FontFaceSet* fonts = static_cast<FontFaceSet*>(SupplementType::from(document, supplementName())))
         fonts->didLayout();
 }
 
 
 } // namespace WebCore