Make the Sk GL context class an abstract base class

src/gpu/gl/nacl/SkNativeGLContext_nacl.cpp

-
-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#include "gl/SkNativeGLContext.h"
-
-SkNativeGLContext::AutoContextRestore::AutoContextRestore() {
-}
-
-SkNativeGLContext::AutoContextRestore::~AutoContextRestore() {
-}
-
-SkNativeGLContext::SkNativeGLContext()
-    : fContext(NULL)
-    , fDisplay(NULL)
-{
-}
-
-SkNativeGLContext::~SkNativeGLContext() {
-    this->destroyGLContext();
-}
-
-void SkNativeGLContext::destroyGLContext() {
-}
-
-const GrGLInterface* SkNativeGLContext::createGLContext(GrGLStandard forcedGpuAPI) {
-    return NULL;
-}
-
-void SkNativeGLContext::makeCurrent() const {
-}
-
-void SkNativeGLContext::swapBuffers() const {
-}