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

runtime/embedders/openglui/common/vm_glue.h

 // Copyright (c) 2012, 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.
 
 #ifndef EMBEDDERS_OPENGLUI_COMMON_VM_GLUE_H_
 #define EMBEDDERS_OPENGLUI_COMMON_VM_GLUE_H_
 
 #include <stdlib.h>
 
 #include "embedders/openglui/common/events.h"
@@ skipping 18 matching lines @@
   int OnMotionEvent(const char* funtion, int64_t when,
                     float move_x, float move_y);
   int OnKeyEvent(const char* funtion, int64_t when, int32_t flags,
              int32_t key_code, int32_t meta_state, int32_t repeat);
   void FinishMainIsolate();
 
  private:
   int Invoke(const char *function, int argc, Dart_Handle* args,
              bool failIfNotDefined = true);
 
-  static int ErrorExit(const char* format, ...);
   static Dart_Handle CheckError(Dart_Handle);
 
   static bool CreateIsolateAndSetupHelper(const char* script_uri,
                                           const char* main,
                                           void* data,
                                           char** error);
   static bool CreateIsolateAndSetup(const char* script_uri,
                                     const char* main,
                                     void* data, char** error);
   static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag,
                                        Dart_Handle library,
                                        Dart_Handle urlHandle);
   static Dart_Handle LoadSourceFromFile(const char* url);
   static void ShutdownIsolate(void* callback_data);
 
   ISized* surface_;
   Dart_Isolate isolate_;
   bool initialized_vm_;
   bool initialized_script_;
   char* main_script_;
   static char* extension_script_;
 };
 
 #endif  // EMBEDDERS_OPENGLUI_COMMON_VM_GLUE_H_