 => {
    // Verify that the placeholder was not updated synchronously.
    assertWidthAndHeight(image, "imagebitmap from placeholder canvas", 10, 20);
    asyncStepsCompleted++;
    if (asyncStepsCompleted == 2) {
      finishTest();
    }
  });

  // Set timeout acts as a sync barrier to allow commit to propagate
  setTimeout(function() {
    // Verify that commit() asynchronously updates the size of its placeholder canvas.
    assertWidthAndHeight(placeholder, "placeholder canvas", 30, 40);

    // Verif