diff -r 000000000000 -r 6474c204b198 browser/devtools/tilt/test/browser_tilt_utils04.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/tilt/test/browser_tilt_utils04.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,54 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+function test() {
+  let dom = TiltUtils.DOM;
+  ok(dom, "The TiltUtils.DOM wasn't found.");
+
+
+  is(dom.initCanvas(), null,
+    "The initCanvas() function shouldn't work if no parent node is set.");
+
+
+  dom.parentNode = gBrowser.parentNode;
+  ok(dom.parentNode,
+    "The necessary parent node wasn't found.");
+
+
+  let canvas = dom.initCanvas(null, {
+    append: true,
+    focusable: true,
+    width: 123,
+    height: 456,
+    id: "tilt-test-canvas"
+  });
+
+  is(canvas.width, 123,
+    "The test canvas doesn't have the correct width set.");
+  is(canvas.height, 456,
+    "The test canvas doesn't have the correct height set.");
+  is(canvas.getAttribute("tabindex"), 1,
+    "The test canvas tab index wasn't set correctly.");
+  is(canvas.getAttribute("id"), "tilt-test-canvas",
+    "The test canvas doesn't have the correct id set.");
+  ok(dom.parentNode.ownerDocument.getElementById(canvas.id),
+    "A canvas should be appended to the parent node if specified.");
+  canvas.parentNode.removeChild(canvas);
+
+  let canvas2 = dom.initCanvas(null, { id: "tilt-test-canvas2" });
+
+  is(canvas2.width, dom.parentNode.clientWidth,
+    "The second test canvas doesn't have the implicit width set.");
+  is(canvas2.height, dom.parentNode.clientHeight,
+    "The second test canvas doesn't have the implicit height set.");
+  is(canvas2.id, "tilt-test-canvas2",
+    "The second test canvas doesn't have the correct id set.");
+  is(dom.parentNode.ownerDocument.getElementById(canvas2.id), null,
+    "A canvas shouldn't be appended to the parent node if not specified.");
+
+
+  dom.parentNode = null;
+  is(dom.parentNode, null,
+    "The necessary parent node shouldn't be found anymore.");
+}