output.diff

diff --git a/browser/base/content/content.js b/browser/base/content/content.js
--- a/browser/base/content/content.js
+++ b/browser/base/content/content.js
@@ -67,8 +67,12 @@ addEventListener("DOMAutoComplete", func
 ContentMetaHandler.init(this);
 
 // This is a temporary hack to prevent regressions (bug 1471327).
 void content;
 
 addEventListener("DOMWindowFocus", function(event) {
   sendAsyncMessage("DOMWindowFocus", {});
 }, false);
+
+addEventListener("mconleytest", function() {
+  dump("Saw the event!\n\n");
+}, true, true);
diff --git a/toolkit/content/widgets/videocontrols.js b/toolkit/content/widgets/videocontrols.js
--- a/toolkit/content/widgets/videocontrols.js
+++ b/toolkit/content/widgets/videocontrols.js
@@ -1285,16 +1285,17 @@ this.VideoControlsImplPageWidget = class
         // controlling volume.
       },
 
       get isVideoInFullScreen() {
         return this.document.mozFullScreenElement == this.shadowRoot.host;
       },
 
       toggleFullscreen() {
+        this.videocontrols.dispatchEvent(new this.window.CustomEvent("mconleytest"));
         this.isVideoInFullScreen ?
           this.document.mozCancelFullScreen() :
           this.video.mozRequestFullScreen();
       },
 
       setFullscreenButtonState() {
         if (this.isAudioOnly || !this.document.mozFullScreenEnabled) {
           this.controlBar.setAttribute("fullscreen-unavailable", true);