fix typeface leak

TBR=bungeman@google.com

Review URL: https://codereview.chromium.org/1239303003
diff --git a/tools/sk_tool_utils.h b/tools/sk_tool_utils.h
index 921ca2a..2bef19d 100644
--- a/tools/sk_tool_utils.h
+++ b/tools/sk_tool_utils.h
@@ -25,7 +25,7 @@
 
     const char* colortype_name(SkColorType);
     SkColor color_to_565(SkColor color);
-    SkTypeface* emoji_typeface();
+    void emoji_typeface(SkAutoTUnref<SkTypeface>* );
     const char* emoji_sample_text();
     const char* platform_os_emoji();
     const char* platform_os_name();