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/tools/flags/SkCommandLineFlags.cpp b/tools/flags/SkCommandLineFlags.cpp
index b088b4e..084f48a 100644
--- a/tools/flags/SkCommandLineFlags.cpp
+++ b/tools/flags/SkCommandLineFlags.cpp
@@ -278,7 +278,7 @@
                             flag->setDouble(atof(argv[i]));
                             break;
                         default:
-                            SkASSERT(!"Invalid flag type");
+                            SkDEBUGFAIL("Invalid flag type");
                     }
                     break;
                 }