Initiate webfont download right after style recalc

Source/core/css/CSSFontFace.h

Index: Source/core/css/CSSFontFace.h
diff --git a/Source/core/css/CSSFontFace.h b/Source/core/css/CSSFontFace.h
index b547667e8a2558f9397d7e13b03904f785b73b22..26a76a0ccc5a7c856a6309db3c1aa20d861c8160 100644
--- a/Source/core/css/CSSFontFace.h
+++ b/Source/core/css/CSSFontFace.h
@@ -84,10 +84,11 @@ public:
     public:
         void add(UChar32 from, UChar32 to) { m_ranges.append(UnicodeRange(from, to)); }
         bool intersectsWith(const String&) const;
+        bool isEntireRange() const { return m_ranges.isEmpty(); }
         size_t size() const { return m_ranges.size(); }
         const UnicodeRange& rangeAt(size_t i) const { return m_ranges[i]; }
     private:
-        Vector<UnicodeRange> m_ranges;
+        Vector<UnicodeRange> m_ranges; // If empty, represents the whole code space.
     };
 
     FontFace::LoadStatus loadStatus() const { return m_fontFace ? m_fontFace->loadStatus() : FontFace::Loaded; }