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

BUG=368107
R=jvanverth@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/254083002

git-svn-id: http://skia.googlecode.com/svn/trunk@14452 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index b5da4d3..7efa067 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -227,6 +227,9 @@
     }
 
     GrGLVersion glVer = GrGLGetVersion(this);
+    if (GR_GL_INVALID_VER == glVer) {
+        RETURN_FALSE_INTERFACE
+    }
 
     // Now check that baseline ES/Desktop fns not covered above are present
     // and that we have fn pointers for any advertised fExtensions that we will