<!DOCTYPE html>
<html>
<style>
    canvas {
        width: 100px;
        height: 100px;
    }
</style>    
<body>
    <div>
        <p>Frames of a 3-frame animated image with missing loopCount, (repetitionCount = 1):</p>
        <canvas id="canvas-1"></canvas>
        <canvas id="canvas-2"></canvas>
        <canvas id="canvas-3"></canvas>
        <canvas id="canvas-4"></canvas>
    </div>
    <div>
        <p>Frames of a 3-frame animated image with loopCount = 1, (repetitionCount = 2):</p>
        <canvas id="canvas-a"></canvas>
        <canvas id="canvas-b"></canvas>
        <canvas id="canvas-c"></canvas>
        <canvas id="canvas-d"></canvas>
        <canvas id="canvas-e"></canvas>
        <canvas id="canvas-f"></canvas>
        <canvas id="canvas-g"></canvas>
    </div>
    <div>
        <p>Frames of a 3-frame animated image with loopCount = 0, (repetitionCount = infinite):</p>
        <canvas id="canvas-A"></canvas>
        <canvas id="canvas-B"></canvas>
        <canvas id="canvas-C"></canvas>
        <canvas id="canvas-D"></canvas>
        <canvas id="canvas-E"></canvas>
        <canvas id="canvas-F"></canvas>
        <canvas id="canvas-G"></canvas>
    </div>
    <script>
        function drawFrame(image, canvasId) {
            return new Promise((resolve) => {
                let canvas = document.getElementById("canvas-" + canvasId);
                let context = canvas.getContext("2d");
                context.drawImage(image, 0, 0, canvas.width, canvas.height);
                setTimeout(() => {
                    resolve(String.fromCharCode(canvasId.charCodeAt() + 1));
                }, 30);
            });
        }

        function drawImage(image, canvasId, frameCount) {
            let promise = drawFrame(image, canvasId);
            for (let frame = 1; frame < frameCount; ++frame) {
                promise = promise.then((canvasId) => {
                    return drawFrame(image, canvasId);
                });
            }
            return promise;
        }

        function loadImage(src, canvasId, frameCount) {
            return new Promise((resolve) => {
                let image = new Image;
                image.onload = (() => {
                    drawImage(image, canvasId, frameCount).then(resolve);
                });
                image.src = src;
            });
        }

        (function() {
            if (window.internals)
                internals.clearMemoryCache();

            if (window.testRunner)
                testRunner.waitUntilDone();

            var images = [
                { src: "resources/animated-red-green-blue-repeat-1.gif", canvasId: '1', frameCount: 4 },
                { src: "resources/animated-red-green-blue-repeat-2.gif", canvasId: 'a', frameCount: 7 },
                { src: "resources/animated-red-green-blue-repeat-infinite.gif", canvasId: 'A', frameCount: 7 }
            ];

            var promises = [];

            for (let image of images)
                promises.push(loadImage(image.src, image.canvasId, image.frameCount));
            
            Promise.all(promises).then(() => {
                if (window.testRunner)
                    testRunner.notifyDone();
            });
        })();
    </script>
</body>
</html>