Add GLFW support for GrGLCreateNativeInterface

src/gpu/gl/glfw/GrGLCreateNativeInterface_glfw.cpp

 /*
- * Copyright 2014 Google Inc.
+ * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "gl/GrGLInterface.h"
 #include "gl/GrGLAssembleInterface.h"
 #include "gl/GrGLUtil.h"
 
-#include <GL/glx.h>
+#include <GLFW/glfw3.h>
 
-static GrGLFuncPtr glx_get(void* ctx, const char name[]) {
+static GrGLFuncPtr glfw_get(void* ctx, const char name[]) {
     SkASSERT(nullptr == ctx);
-    SkASSERT(glXGetCurrentContext());
-    return glXGetProcAddress(reinterpret_cast<const GLubyte*>(name));
+    SkASSERT(glfwGetCurrentContext());
+    return glfwGetProcAddress(name);
 }
 
 const GrGLInterface* GrGLCreateNativeInterface() {
-    if (nullptr == glXGetCurrentContext()) {
+    if (nullptr == glfwGetCurrentContext()) {
         return nullptr;
     }
 
-    return GrGLAssembleInterface(nullptr, glx_get);
+    return GrGLAssembleInterface(nullptr, glfw_get);
 }