Use unicode-range to prevent unnecessary @font-face donwnloads

Source/core/platform/graphics/FontFallbackList.cpp

 /*
  * Copyright (C) 2006 Apple Computer, 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
@@ skipping 70 matching lines @@
     else {
         const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
         unsigned numRanges = segmentedFontData->numRanges();
         if (numRanges == 1)
             m_pitch = segmentedFontData->rangeAt(0).fontData()->pitch();
         else
             m_pitch = VariablePitch;
     }
 }
 
+bool FontFallbackList::loadingCustomFonts() const
+{
+    if (m_loadingCustomFonts)
+        return true;
+
+    unsigned numFonts = m_fontList.size();
+    for (unsigned i = 0; i < numFonts; ++i) {
+        if (m_fontList[i]->isCustomFont() && m_fontList[i]->isLoading()) {
+            m_loadingCustomFonts = true;

[dglazkov, 2013/09/10 15:26:41]

This smells wrong. Why does a const getter modify state? It seems that we're
just using m_loadingCustomFonts as a memoizer for this function. I think we
should split these concerns up: one method to ensure m_loadingCustomFonts, one
to query it. The fontDataAt does sort of the same thing.

[Kunihiko Sakamoto, 2013/09/11 13:28:09]

Now FontData in m_fontList can change its loading state by getting used, so we
cannot simply calculate m_loadingCustomFonts once at first. Maybe we should make
this function non-const?

+            return true;
+        }
+    }
+    return false;
+}
+
 const FontData* FontFallbackList::fontDataAt(const Font* font, unsigned realizedFontIndex) const
 {
     if (realizedFontIndex < m_fontList.size())
         return m_fontList[realizedFontIndex].get(); // This fallback font is already in our list.
 
     // Make sure we're not passing in some crazy value here.
     ASSERT(realizedFontIndex == m_fontList.size());
 
     if (m_familyIndex == cAllFamiliesScanned)
         return 0;
@@ skipping 14 matching lines @@
 
 void FontFallbackList::setPlatformFont(const FontPlatformData& platformData)
 {
     m_familyIndex = cAllFamiliesScanned;
     ASSERT(fontCache()->generation() == m_generation);
     RefPtr<FontData> fontData = fontCache()->getFontResourceData(&platformData);
     m_fontList.append(fontData);
 }
 
 }