Clarify desired behavior of FontConfigTypeface::LegacyCreateTypeface.

src/fonts/SkFontMgr_fontconfig.cpp

Index: src/fonts/SkFontMgr_fontconfig.cpp
diff --git a/src/fonts/SkFontMgr_fontconfig.cpp b/src/fonts/SkFontMgr_fontconfig.cpp
index ba2dae8be346ad71a9d69757b7c2453aeb221267..9f436812a81f133acd3e0809f08bbf8af52ef5a5 100644
--- a/src/fonts/SkFontMgr_fontconfig.cpp
+++ b/src/fonts/SkFontMgr_fontconfig.cpp
@@ -324,8 +324,7 @@ protected:
     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],
                                                unsigned styleBits) const SK_OVERRIDE {
         FCLocker lock;
-        return FontConfigTypeface::LegacyCreateTypeface(NULL, familyName,
-                                                  (SkTypeface::Style)styleBits);
+        return FontConfigTypeface::LegacyCreateTypeface(familyName, (SkTypeface::Style)styleBits);
     }
 };