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/src/utils/SkPictureUtils.cpp b/src/utils/SkPictureUtils.cpp
index 87a4057..45d3f1b 100644
--- a/src/utils/SkPictureUtils.cpp
+++ b/src/utils/SkPictureUtils.cpp
@@ -37,7 +37,7 @@
 };
 
 static void not_supported() {
-    SkASSERT(!"this method should never be called");
+    SkDEBUGFAIL("this method should never be called");
 }
 
 static void nothing_to_do() {}