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

BUG=
R=robertphillips@google.com

Review URL: https://codereview.chromium.org/22875037

git-svn-id: http://skia.googlecode.com/svn/trunk@10874 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/GradientBench.cpp b/bench/GradientBench.cpp
index b20fc9a..773522e 100644
--- a/bench/GradientBench.cpp
+++ b/bench/GradientBench.cpp
@@ -137,7 +137,7 @@
         case SkShader::kMirror_TileMode:
             return "mirror";
         default:
-            SkASSERT(!"unknown tilemode");
+            SkDEBUGFAIL("unknown tilemode");
             return "error";
     }
 }
@@ -149,7 +149,7 @@
         case kOval_GeomType:
             return "oval";
         default:
-            SkASSERT(!"unknown geometry type");
+            SkDEBUGFAIL("unknown geometry type");
             return "error";
     }
 }