title: js canvas create pattern repeat issues
body: <p>Currently drawing this onto a canvas:</p>
  <p><a href="https://i.stack.imgur.com/eS1Kj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eS1Kj.png" alt="enter image description here" /></a></p>
  <p>I want to use a texture that repeats only on the Y axis where the red rectangle is.</p>
  <p>However, when drawing the texture, nothing shows up when <code>repeat-y</code> is specified. It works when the repeat value is <code>repeat</code> however.</p>
  <pre><code>ctx.fillStyle = ctx.createPattern(assets.grassRightTexture, 'repeat-y');
  ctx.fillRect(dimensions.left + dimensions.width, dimensions.top, 5, dimensions.height);
  </code></pre>
  <p>The <code>assets.grassRightTexture</code> is a preloaded img element with a 4px by 32px sprite.</p>
  <p>Not sure if im doing something wrong but I didnt notice anything when reading the moz canvas docs.</p>
  <p>Thank you.</p>