My clang now doesn't complain about !"foo".

src/gpu/SkGrFontScaler.cpp

Index: src/gpu/SkGrFontScaler.cpp
diff --git a/src/gpu/SkGrFontScaler.cpp b/src/gpu/SkGrFontScaler.cpp
index aeddd280e7d5bba109715555ed26d1406da8bab2..c48e633fd0a4cd09dbb0b06c06ccf5fe8a5775ae 100644
--- a/src/gpu/SkGrFontScaler.cpp
+++ b/src/gpu/SkGrFontScaler.cpp
@@ -88,7 +88,7 @@ GrMaskFormat SkGrFontScaler::getMaskFormat() {
         case SkMask::kLCD32_Format:
             return kA888_GrMaskFormat;
         default:
-            SkASSERT(!"unsupported SkMask::Format");
+            SkDEBUGFAIL("unsupported SkMask::Format");
             return kA8_GrMaskFormat;
     }
 }