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

runtime/embedders/openglui/common/gl_graphics_handler.h

-// 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.
-
-#ifndef EMBEDDERS_OPENGLUI_COMMON_GL_GRAPHICS_HANDLER_H_
-#define EMBEDDERS_OPENGLUI_COMMON_GL_GRAPHICS_HANDLER_H_
-
-#include "embedders/openglui/common/graphics_handler.h"
-#include "embedders/openglui/common/opengl.h"
-#include "embedders/openglui/common/timer.h"
-
-class GLGraphicsHandler : public GraphicsHandler {
-  public:
-    GLGraphicsHandler()
-      : GraphicsHandler() {
-    }
-
-    virtual int32_t Start() = 0;
-    virtual void Stop() = 0;
-
-    void SwapBuffers() {
-      GLSwapBuffers();
-    }
-
-    virtual int32_t Update() {
-      SwapBuffers();
-      return 0;
-    }
-
-    void SetViewport(int left, int top, int width, int height);
-    int BuildProgram(const char* vertexShaderSource,
-                     const char* fragmentShaderSource) const;
-    int BuildShader(const char* source, GLenum shaderType) const;
-
-    virtual ~GLGraphicsHandler() {
-    }
-};
-
-#endif  // EMBEDDERS_OPENGLUI_COMMON_GL_GRAPHICS_HANDLER_H_
-