Render Unicode control characters

third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp

Index: third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
diff --git a/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp b/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
index 1e37b6da42b1c79077ed11bf98e1d6eb49a3679b..34879c83c2d454826203bef3227885c6173c8de2 100644
--- a/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
+++ b/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
@@ -182,14 +182,13 @@ const PassRefPtr<SimpleFontData> FontFallbackIterator::fallbackPriorityFont(
 
 const PassRefPtr<SimpleFontData> FontFallbackIterator::uniqueSystemFontForHint(UChar32 hint)
 {
-    FontCache* fontCache = FontCache::fontCache();
-
     // When we're asked for a fallback for the same characters again, we give up
     // because the shaper must have previously tried shaping with the font
     // already.
-    if (m_previouslyAskedForHint.contains(hint))
+    if (!hint || m_previouslyAskedForHint.contains(hint))
         return nullptr;
 
+    FontCache* fontCache = FontCache::fontCache();
     m_previouslyAskedForHint.add(hint);
     return fontCache->fallbackFontForCharacter(m_fontDescription, hint, m_fontFallbackList->primarySimpleFontData(m_fontDescription));
 }