diff -r 000000000000 -r 6474c204b198 browser/base/content/test/plugins/browser_CTP_resize.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/plugins/browser_CTP_resize.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,116 @@
+var rootDir = getRootDirectory(gTestPath);
+const gTestRoot = rootDir;
+const gHttpTestRoot = rootDir.replace("chrome://mochitests/content/", "http://127.0.0.1:8888/");
+
+var gTestBrowser = null;
+var gNextTest = null;
+var gPluginHost = Components.classes["@mozilla.org/plugin/host;1"].getService(Components.interfaces.nsIPluginHost);
+
+Components.utils.import("resource://gre/modules/Services.jsm");
+
+function test() {
+  waitForExplicitFinish();
+  registerCleanupFunction(function() {
+    clearAllPluginPermissions();
+    Services.prefs.clearUserPref("extensions.blocklist.suppressUI");
+  });
+  Services.prefs.setBoolPref("extensions.blocklist.suppressUI", true);
+
+  var newTab = gBrowser.addTab();
+  gBrowser.selectedTab = newTab;
+  gTestBrowser = gBrowser.selectedBrowser;
+  gTestBrowser.addEventListener("load", pageLoad, true);
+
+  Services.prefs.setBoolPref("plugins.click_to_play", true);
+  setTestPluginEnabledState(Ci.nsIPluginTag.STATE_CLICKTOPLAY);
+
+  prepareTest(runAfterPluginBindingAttached(test1), gHttpTestRoot + "plugin_small.html");
+}
+
+function finishTest() {
+  clearAllPluginPermissions();
+  gTestBrowser.removeEventListener("load", pageLoad, true);
+  gBrowser.removeCurrentTab();
+  window.focus();
+  finish();
+}
+
+function pageLoad() {
+  // The plugin events are async dispatched and can come after the load event
+  // This just allows the events to fire before we then go on to test the states
+  executeSoon(gNextTest);
+}
+
+function prepareTest(nextTest, url) {
+  gNextTest = nextTest;
+  gTestBrowser.contentWindow.location = url;
+}
+
+// Due to layout being async, "PluginBindAttached" may trigger later.
+// This wraps a function to force a layout flush, thus triggering it,
+// and schedules the function execution so they're definitely executed
+// afterwards.
+function runAfterPluginBindingAttached(func) {
+  return function() {
+    let doc = gTestBrowser.contentDocument;
+    let elems = doc.getElementsByTagName('embed');
+    if (elems.length < 1) {
+      elems = doc.getElementsByTagName('object');
+    }
+    elems[0].clientTop;
+    executeSoon(func);
+  };
+}
+
+// Test that the overlay is hidden for "small" plugin elements and is shown
+// once they are resized to a size that can hold the overlay
+
+function test1() {
+  let popupNotification = PopupNotifications.getNotification("click-to-play-plugins", gTestBrowser);
+  ok(popupNotification, "Test 1, Should have a click-to-play notification");
+
+  let plugin = gTestBrowser.contentDocument.getElementById("test");
+  let doc = gTestBrowser.contentDocument;
+  let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+  ok(overlay, "Test 1, Should have an overlay.");
+  ok(!overlay.classList.contains("visible"), "Test 1, Overlay should be hidden");
+
+  plugin.style.width = '300px';
+  executeSoon(test2);
+}
+
+function test2() {
+  let plugin = gTestBrowser.contentDocument.getElementById("test");
+  let doc = gTestBrowser.contentDocument;
+  let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+  ok(overlay, "Test 2, Should have an overlay.");
+  ok(!overlay.classList.contains("visible"), "Test 2, Overlay should be hidden");
+
+  plugin.style.height = '300px';
+  let condition = () => overlay.classList.contains("visible");
+  waitForCondition(condition, test3, "Test 2, Waited too long for overlay to become visible");
+}
+
+function test3() {
+  let plugin = gTestBrowser.contentDocument.getElementById("test");
+  let doc = gTestBrowser.contentDocument;
+  let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+  ok(overlay, "Test 3, Should have an overlay.");
+  ok(overlay.classList.contains("visible"), "Test 3, Overlay should be visible");
+
+  plugin.style.width = '10px';
+  plugin.style.height = '10px';
+  let condition = () => !overlay.classList.contains("visible");
+  waitForCondition(condition, test4, "Test 3, Waited too long for overlay to become hidden");
+}
+
+function test4() {
+  let plugin = gTestBrowser.contentDocument.getElementById("test");
+  let doc = gTestBrowser.contentDocument;
+  let overlay = doc.getAnonymousElementByAttribute(plugin, "anonid", "main");
+  ok(overlay, "Test 4, Should have an overlay.");
+  ok(!overlay.classList.contains("visible"), "Test 4, Overlay should be hidden");
+
+  clearAllPluginPermissions();
+  finishTest();
+}