Use glGetStringi to get extensions when available.

src/gpu/gl/GrGLNoOpInterface.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLNoOpInterface_DEFINED
 #define GrGLNoOpInterface_DEFINED
 
@@ skipping 317 matching lines @@
 GrGLvoid GR_GL_FUNCTION_TYPE noOpGLGetQueryObjectui64v(GrGLuint id,
                                                        GrGLenum pname,
                                                        GrGLuint64 *params);
 
 GrGLvoid GR_GL_FUNCTION_TYPE noOpGLGetQueryObjectuiv(GrGLuint id,
                                                      GrGLenum pname,
                                                      GrGLuint *params);
 
 const GrGLubyte* GR_GL_FUNCTION_TYPE noOpGLGetString(GrGLenum name);
 
+const GrGLubyte* GR_GL_FUNCTION_TYPE noOpGLGetStringi(GrGLenum name, GrGLuint i);
+
 GrGLvoid GR_GL_FUNCTION_TYPE noOpGLGetTexLevelParameteriv(GrGLenum target,
                                                           GrGLint level,
                                                           GrGLenum pname,
                                                           GrGLint* params);
 
 GrGLint GR_GL_FUNCTION_TYPE noOpGLGetUniformLocation(GrGLuint program, const char* name);
 
 #endif