Replace NULL with nullptr in call to GrGLExtensions::init

gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/skia_bindings/gl_bindings_skia_cmd_buffer.h"
 
 #ifndef GL_GLEXT_PROTOTYPES
 #define GL_GLEXT_PROTOTYPES
 #endif
 #include "base/logging.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/skia/include/gpu/gl/GrGLInterface.h"
 
 namespace skia_bindings {
 
 void InitCommandBufferSkiaGLBinding(GrGLInterface* interface) {
   interface->fStandard = kGLES_GrGLStandard;
   interface->fExtensions.init(kGLES_GrGLStandard,
                               glGetString,
-                              NULL,
+                              nullptr,
                               glGetIntegerv);
 
   GrGLInterface::Functions* functions = &interface->fFunctions;
   functions->fActiveTexture = glActiveTexture;
   functions->fAttachShader = glAttachShader;
   functions->fBindAttribLocation = glBindAttribLocation;
   functions->fBindBuffer = glBindBuffer;
   functions->fBindTexture = glBindTexture;
   functions->fBindVertexArray = glBindVertexArrayOES;
   functions->fBlendBarrier = glBlendBarrierKHR;
@@ skipping 140 matching lines @@
       glStencilThenCoverFillPathInstancedCHROMIUM;
   functions->fStencilThenCoverStrokePathInstanced =
       glStencilThenCoverStrokePathInstancedCHROMIUM;
   functions->fProgramPathFragmentInputGen =
       glProgramPathFragmentInputGenCHROMIUM;
   functions->fBindFragmentInputLocation = glBindFragmentInputLocationCHROMIUM;
   functions->fCoverageModulation = glCoverageModulationCHROMIUM;
 }
 
 }  // namespace skia