Have FontFallbackList::primaryFontData always return font data

Source/core/platform/graphics/FontFallbackList.cpp

Index: Source/core/platform/graphics/FontFallbackList.cpp
diff --git a/Source/core/platform/graphics/FontFallbackList.cpp b/Source/core/platform/graphics/FontFallbackList.cpp
index 51a655c8c632e45540d5197f12d0d845f26cb290..cfd5eb87a7055c08a4ba9a00498588bc781ae53e 100644
--- a/Source/core/platform/graphics/FontFallbackList.cpp
+++ b/Source/core/platform/graphics/FontFallbackList.cpp
@@ -29,6 +29,7 @@
 #include "config.h"
 #include "core/platform/graphics/FontFallbackList.h"
 
+#include "core/platform/graphics/Font.h"
 #include "core/platform/graphics/FontCache.h"
 #include "core/platform/graphics/SegmentedFontData.h"
 
@@ -136,7 +137,7 @@ const FontData* FontFallbackList::fontDataAt(const Font* font, unsigned realized
     ASSERT(realizedFontIndex == m_fontList.size());
 
     if (m_familyIndex == cAllFamiliesScanned)
-        return 0;
+        return fontCache()->getNonRetainedLastResortFallbackFont(font->fontDescription());
 
     // Ask the font cache for the font data.
     // We are obtaining this font for the first time.  We keep track of the families we've looked at before