Canvas API. There are still a number of things to do:

runtime/embedders/openglui/emulator/emulator_embedder.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_embedder.h"
 
 #include <string.h>
-
+#include <sys/time.h>
+#include "embedders/openglui/common/canvas_context.h"
 #include "embedders/openglui/common/context.h"
 #include "embedders/openglui/common/dart_host.h"
 #include "embedders/openglui/common/events.h"
 #include "embedders/openglui/common/input_handler.h"
 #include "embedders/openglui/common/sound_handler.h"
 #include "embedders/openglui/common/vm_glue.h"
 #include "embedders/openglui/emulator/emulator_graphics_handler.h"
 
 InputHandler* input_handler_ptr;
 LifeCycleHandler* lifecycle_handler_ptr;
 
+struct timeval tvStart;
+void tick(int data);
+
 void display() {
-    glClearColor(1.0, 1.0, 1.0, 1.0);
-    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-    lifecycle_handler_ptr->OnStep();
-    glutSwapBuffers();
+  // Get number of msecs since last call.
+  struct timeval tvEnd;
+  gettimeofday(&tvEnd, NULL);
+  uint64_t elapsed = (tvEnd.tv_usec + 1000000 * tvEnd.tv_sec) -
+                 (tvStart.tv_usec + 1000000 * tvStart.tv_sec);
+
+  if (lifecycle_handler_ptr->OnStep() != 0) {
+    exit(-1);
+  }
+  // Schedule next call, trying to aim for 60fps.
+  int delay = 1000 / 60 - (elapsed / 1000);
+  if (delay < 0) delay = 0;
+  tvStart = tvEnd;
+  glutTimerFunc(delay, tick, 0);
+}
+
+void tick(int data) {
+  display();
 }
 
 void reshape(int width, int height) {
-    glViewport(0, 0, width, height);
-    glMatrixMode(GL_PROJECTION);
-    glLoadIdentity();
-    glOrtho(0, width, 0, height, -1, 1);
-    glMatrixMode(GL_MODELVIEW);
-    glutPostRedisplay();
+  glViewport(0, 0, width, height);
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+  glOrtho(0, width, 0, height, -1, 1);
+  glMatrixMode(GL_MODELVIEW);
+  glutPostRedisplay();
 }
 
 void keyboard(unsigned char key, int x, int y) {
   input_handler_ptr->OnKeyEvent(kKeyDown, time(0), 0, key, 0, 0);
   input_handler_ptr->OnKeyEvent(kKeyUp, time(0), 0, key, 0, 0);
   if (key == 27) {
-      exit(0);
+    exit(0);
   }
 }
 
 DART_EXPORT void emulator_main(int argc, char** argv, const char* script) {
   EmulatorGraphicsHandler graphics_handler(argc, argv);
   if (argc > 0) {
     int i = argc - 1;
     size_t len = strlen(argv[i]);
     if (len > 5 && strcmp(".dart", argv[i] + len - 5) == 0) {
       script = argv[i];
     }
   }
   VMGlue vm_glue(&graphics_handler, ".", "gl.dart", script);
   InputHandler input_handler(&vm_glue);
   input_handler_ptr = &input_handler;
   SoundHandler sound_handler;
   Timer timer;
   Context app_context;
   app_context.graphics_handler = &graphics_handler;
   app_context.input_handler = &input_handler;
   app_context.sound_handler = &sound_handler;
   app_context.timer = &timer;
   app_context.vm_glue = &vm_glue;
   DartHost host(&app_context);
   lifecycle_handler_ptr = &host;
-  lifecycle_handler_ptr->OnActivate();
   glutReshapeFunc(reshape);
   glutDisplayFunc(display);
   glutKeyboardFunc(keyboard);
-  glutIdleFunc(display);
+  lifecycle_handler_ptr->OnActivate();
+  gettimeofday(&tvStart, NULL);
+  glutTimerFunc(1, tick, 0);
   glutMainLoop();
 }