Fail to create GrContext when we get a NULL for a GL/GLSL version string

src/gpu/gl/GrGLUtil.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLUtil.h"
 #include "SkMatrix.h"
@@ skipping 122 matching lines @@
     return 4 == n;
 }
 
 bool GrGLIsChromiumFromRendererString(const char* rendererString) {
     return 0 == strcmp(rendererString, "Chromium");
 }
 
 GrGLVersion GrGLGetVersionFromString(const char* versionString) {
     if (NULL == versionString) {
         SkDEBUGFAIL("NULL GL version string.");
-        return 0;
+        return GR_GL_INVALID_VER;
     }
 
     int major, minor;
 
     // check for mesa
     int mesaMajor, mesaMinor;
     int n = sscanf(versionString, "%d.%d Mesa %d.%d", &major, &minor, &mesaMajor, &mesaMinor);
     if (4 == n) {
         if (get_gl_version_for_mesa(mesaMajor, &major, &minor)) {
             return GR_GL_VER(major, minor);
         } else {
-            return 0;
+            return GR_GL_INVALID_VER;
         }
     }
 
     n = sscanf(versionString, "%d.%d", &major, &minor);
     if (2 == n) {
         return GR_GL_VER(major, minor);
     }
 
     char profile[2];
     n = sscanf(versionString, "OpenGL ES-%c%c %d.%d", profile, profile+1,
                &major, &minor);
     if (4 == n) {
         return GR_GL_VER(major, minor);
     }
 
     n = sscanf(versionString, "OpenGL ES %d.%d", &major, &minor);
     if (2 == n) {
         return GR_GL_VER(major, minor);
     }
 
-    return 0;
+    return GR_GL_INVALID_VER;
 }
 
 GrGLSLVersion GrGLGetGLSLVersionFromString(const char* versionString) {
     if (NULL == versionString) {
         SkDEBUGFAIL("NULL GLSL version string.");
-        return 0;
+        return GR_GLSL_INVALID_VER;
     }
 
     int major, minor;
 
     int n = sscanf(versionString, "%d.%d", &major, &minor);
     if (2 == n) {
         return GR_GLSL_VER(major, minor);
     }
 
     n = sscanf(versionString, "OpenGL ES GLSL ES %d.%d", &major, &minor);
     if (2 == n) {
         return GR_GLSL_VER(major, minor);
     }
 
 #ifdef SK_BUILD_FOR_ANDROID
     // android hack until the gpu vender updates their drivers
     n = sscanf(versionString, "OpenGL ES GLSL %d.%d", &major, &minor);
     if (2 == n) {
         return GR_GLSL_VER(major, minor);
     }
 #endif
 
-    return 0;
+    return GR_GLSL_INVALID_VER;
 }
 
 GrGLVendor GrGLGetVendorFromString(const char* vendorString) {
     if (NULL != vendorString) {
         if (0 == strcmp(vendorString, "ARM")) {
             return kARM_GrGLVendor;
         }
         if (0 == strcmp(vendorString, "Imagination Technologies")) {
             return kImagination_GrGLVendor;
         }
@@ skipping 77 matching lines @@
     dest[9]  = 0;
     dest[10] = 1;
     dest[11] = 0;
 
     // Col 3
     dest[12] = SkScalarToFloat(src[SkMatrix::kMTransX]);
     dest[13] = SkScalarToFloat(src[SkMatrix::kMTransY]);
     dest[14] = 0;
     dest[15] = SkScalarToFloat(src[SkMatrix::kMPersp2]);
 }