diff -r 000000000000 -r 6474c204b198 browser/devtools/tilt/test/browser_tilt_05_destruction-esc.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/tilt/test/browser_tilt_05_destruction-esc.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+"use strict";
+
+let tiltOpened = false;
+
+function test() {
+  if (!isTiltEnabled()) {
+    info("Skipping destruction test because Tilt isn't enabled.");
+    return;
+  }
+  if (!isWebGLSupported()) {
+    info("Skipping destruction test because WebGL isn't supported.");
+    return;
+  }
+
+  waitForExplicitFinish();
+
+  createTab(function() {
+    createTilt({
+      onTiltOpen: function()
+      {
+        tiltOpened = true;
+
+        Services.obs.addObserver(finalize, DESTROYED, false);
+        EventUtils.sendKey("ESCAPE");
+      }
+    }, false, function suddenDeath()
+    {
+      info("Tilt could not be initialized properly.");
+      cleanup();
+    });
+  });
+}
+
+function finalize() {
+  let id = TiltUtils.getWindowId(gBrowser.selectedBrowser.contentWindow);
+
+  is(Tilt.visualizers[id], null,
+    "The current instance of the visualizer wasn't destroyed properly.");
+
+  cleanup();
+}
+
+function cleanup() {
+  if (tiltOpened) { Services.obs.removeObserver(finalize, DESTROYED); }
+  gBrowser.removeCurrentTab();
+  finish();
+}