Remove openglui embedder code

runtime/embedders/openglui/emulator/emulator_graphics_handler.cc

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#include "embedders/openglui/emulator/emulator_graphics_handler.h"
-
-#include <stdlib.h>
-#include <string.h>
-
-EmulatorGraphicsHandler::EmulatorGraphicsHandler(int argc,
-                                                 char** argv)
-  : GraphicsHandler(".") {
-  glutInit(&argc, argv);
-  width_ = 800;
-  height_ = 480;
-  for (int i = 1; i < argc; i++) {
-    if (argv[i][0] == '-') {
-      int next_arg = i + 1;
-      if (next_arg < argc && strcmp(argv[i], "-w") == 0) {
-        width_ = static_cast<size_t>(atoi(argv[i = next_arg]));
-      } else if (next_arg < argc && strcmp(argv[i], "-h") == 0) {
-        height_ = static_cast<size_t>(atoi(argv[i = next_arg]));
-      }
-    }
-  }
-  SetViewport(0, 0, width_, height_);
-  glutInitWindowSize(width_, height_);
-  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH | GLUT_STENCIL);
-  glutCreateWindow("Dart");
-}
-
-int32_t EmulatorGraphicsHandler::Start() {
-  return GraphicsHandler::Start();
-}
-
-void EmulatorGraphicsHandler::Stop() {
-  GraphicsHandler::Stop();
-}
-