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 c1c0ca97bf8743bf76e5d49cd9e2574837829d86..30b0d09db4977d82e9acb54345b383bcccf241a2 100644
--- a/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
+++ b/third_party/WebKit/Source/platform/fonts/FontFallbackIterator.cpp
@@ -177,15 +177,13 @@ 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_visitedSystemFonts.find(hint) != m_visitedSystemFonts.end()) {
+    if (!hint || m_visitedSystemFonts.find(hint) != m_visitedSystemFonts.end())
         return nullptr;
-    }
 
+    FontCache* fontCache = FontCache::fontCache();
     RefPtr<SimpleFontData> fallbackFont = fontCache->fallbackFontForCharacter(m_fontDescription, hint, m_fontFallbackList->primarySimpleFontData(m_fontDescription));
 
     return m_visitedSystemFonts.add(hint, fallbackFont).storedValue->value;