diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_bug416661.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_bug416661.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,43 @@
+var tabElm, zoomLevel;
+function start_test_prefNotSet() {
+  Task.spawn(function () {
+    is(ZoomManager.zoom, 1, "initial zoom level should be 1");
+    FullZoom.enlarge();
+
+    //capture the zoom level to test later
+    zoomLevel = ZoomManager.zoom;
+    isnot(zoomLevel, 1, "zoom level should have changed");
+
+    yield FullZoomHelper.load(gBrowser.selectedTab, "http://mochi.test:8888/browser/browser/base/content/test/general/moz.png");
+  }).then(continue_test_prefNotSet, FullZoomHelper.failAndContinue(finish));
+}
+
+function continue_test_prefNotSet () {
+  Task.spawn(function () {
+    is(ZoomManager.zoom, 1, "zoom level pref should not apply to an image");
+    FullZoom.reset();
+
+    yield FullZoomHelper.load(gBrowser.selectedTab, "http://mochi.test:8888/browser/browser/base/content/test/general/zoom_test.html");
+  }).then(end_test_prefNotSet, FullZoomHelper.failAndContinue(finish));
+}
+
+function end_test_prefNotSet() {
+  Task.spawn(function () {
+    is(ZoomManager.zoom, zoomLevel, "the zoom level should have persisted");
+
+    // Reset the zoom so that other tests have a fresh zoom level
+    FullZoom.reset();
+    yield FullZoomHelper.removeTabAndWaitForLocationChange();
+    finish();
+  });
+}
+
+function test() {
+  waitForExplicitFinish();
+
+  Task.spawn(function () {
+    tabElm = gBrowser.addTab();
+    yield FullZoomHelper.selectTabAndWaitForLocationChange(tabElm);
+    yield FullZoomHelper.load(tabElm, "http://mochi.test:8888/browser/browser/base/content/test/general/zoom_test.html");
+  }).then(start_test_prefNotSet, FullZoomHelper.failAndContinue(finish));
+}