third_party/skia/demos.skia.org/demos/web_worker/index.html - cobalt - Git at Google

 <!DOCTYPE html>
 <title>CanvasKit Web Worker Demo</title>
 <meta charset="utf-8" />
 <meta http-equiv="X-UA-Compatible" content="IE=edge">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">

 <style>
   canvas {
     border: 1px dashed grey;
   }

   .canvas-container {
     float: left;
   }
 </style>

 <body>
   <h1>CanvasKit in a Web Worker demo</h1>
   <p>NOTE: this demo currently only works in chromium-based browsers, where
     <a href="https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas#Browser_compatibility">
       Offscreen Canvas
     </a>
     is supported.
   </p>

   <div class="canvas-container">
     <h2>Normal Canvas</h2>
     <canvas id="onscreen-canvas" width=500 height=500></canvas>
     <button id="busy-button">Make main thread busy</button>
   </div>
   <div class="canvas-container">
     <h2>Web Worker Canvas</h2>
     <canvas id="offscreen-canvas" width=500 height=500></canvas>
   </div>
 </body>
 <script type="text/javascript" src="https://unpkg.com/canvaskit-wasm@0.25.0/bin/full/canvaskit.js"></script>
 <script type="text/javascript" src="shared.js"></script>
 <script type="text/javascript" src="main.js"></script>
	<!DOCTYPE html>
	<title>CanvasKit Web Worker Demo</title>
	<meta charset="utf-8" />
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">

	<style>
	canvas {
	border: 1px dashed grey;
	}

	.canvas-container {
	float: left;
	}
	</style>

	<body>
	<h1>CanvasKit in a Web Worker demo</h1>
	<p>NOTE: this demo currently only works in chromium-based browsers, where
	<a href="https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas#Browser_compatibility">
	Offscreen Canvas
	</a>
	is supported.
	</p>

	<div class="canvas-container">
	<h2>Normal Canvas</h2>
	<canvas id="onscreen-canvas" width=500 height=500></canvas>
	<button id="busy-button">Make main thread busy</button>
	</div>
	<div class="canvas-container">
	<h2>Web Worker Canvas</h2>
	<canvas id="offscreen-canvas" width=500 height=500></canvas>
	</div>
	</body>
	<script type="text/javascript" src="https://unpkg.com/canvaskit-wasm@0.25.0/bin/full/canvaskit.js"></script>
	<script type="text/javascript" src="shared.js"></script>
	<script type="text/javascript" src="main.js"></script>