Bug 817700 - Fix test_mozGetAsFile canvas test. r=roc

<canvas id="c" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>

<script>

var gCompares = 0;

function compareAsync(file, canvas, type)

function compareAsync(file, canvas, type, callback)

{

  ++gCompares;

  var reader = new FileReader();

  reader.onload = 

    function(e) {

      is(e.target.result, canvas.toDataURL(type),

 "<canvas>.mozGetAsFile().getAsDataURL() should equal <canvas>.toDataURL()");

      if (--gCompares == 0) {

        SimpleTest.finish();

      }

      callback(canvas);

    };

  reader.readAsDataURL(file);

}

SimpleTest.waitForExplicitFinish();

addLoadEvent(function () {

var canvas = document.getElementById('c');

var ctx = canvas.getContext('2d');

ctx.drawImage(document.getElementById('yellow75.png'), 0, 0);

function test1(canvas)

{

  var pngfile = canvas.mozGetAsFile("foo.png");

  is(pngfile.type, "image/png", "Default type for mozGetAsFile should be PNG");

compareAsync(pngfile, canvas, "image/png");

  compareAsync(pngfile, canvas, "image/png", test2);

  is(pngfile.name, "foo.png", "File name should be what we passed in");

}

function test2(canvas)

{

  var jpegfile = canvas.mozGetAsFile("bar.jpg", "image/jpeg");

  is(jpegfile.type, "image/jpeg",

     "When a valid type is specified that should be returned");

compareAsync(jpegfile, canvas, "image/jpeg");

  compareAsync(jpegfile, canvas, "image/jpeg", SimpleTest.finish);

  is(jpegfile.name, "bar.jpg", "File name should be what we passed in");

}

SimpleTest.waitForExplicitFinish();

addLoadEvent(function () {

var canvas = document.getElementById('c');

var ctx = canvas.getContext('2d');

ctx.drawImage(document.getElementById('yellow75.png'), 0, 0);

test1(canvas);

});

</script>