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/gpu/gl/GrGLUtil.cpp b/src/gpu/gl/GrGLUtil.cpp
index 99efeaf..422f0c3 100644
--- a/src/gpu/gl/GrGLUtil.cpp
+++ b/src/gpu/gl/GrGLUtil.cpp
@@ -93,7 +93,7 @@
 
 GrGLBinding GrGLGetBindingInUseFromString(const char* versionString) {
     if (NULL == versionString) {
-        SkASSERT(!"NULL GL version string.");
+        SkDEBUGFAIL("NULL GL version string.");
         return kNone_GrGLBinding;
     }
 
@@ -129,7 +129,7 @@
 
 GrGLVersion GrGLGetVersionFromString(const char* versionString) {
     if (NULL == versionString) {
-        SkASSERT(!"NULL GL version string.");
+        SkDEBUGFAIL("NULL GL version string.");
         return 0;
     }
 
@@ -168,7 +168,7 @@
 
 GrGLSLVersion GrGLGetGLSLVersionFromString(const char* versionString) {
     if (NULL == versionString) {
-        SkASSERT(!"NULL GLSL version string.");
+        SkDEBUGFAIL("NULL GLSL version string.");
         return 0;
     }