Bug 1543128 - Fire UAWidgetSetupOrChange for the no-controls <video> case on Desktop. r=jya

The Picture-in-Picture toggle buttons are now part of the video controls UAWidget
bindings, so we need to construct a UAWidget for the no-controls case for Desktop
to make that toggle available.

Up until now, we've never needed a no-controls UAWidget for Desktop, since we
never needed to show UI in that case.

Depends on D26809

Differential Revision: https://phabricator.services.mozilla.com/D26803

--HG--
extra : moz-landing-system : lando

dom/html/HTMLMediaElement.cpp

@@ -4097,19 +4097,7 @@ nsresult HTMLMediaElement::BindToTree(Document* aDocument, nsIContent* aParent,
   if (IsInComposedDoc()) {
     // Construct Shadow Root so web content can be hidden in the DOM.
     AttachAndSetUAShadowRoot();
-#ifdef ANDROID
     NotifyUAWidgetSetupOrChange();
-#else
-    // We don't want to call into JS if the website never asks for native
-    // video controls.
-    // If controls attribute is set later, controls is constructed lazily
-    // with the UAWidgetAttributeChanged event.
-    // This only applies to Desktop because on Fennec we would need to show
-    // an UI if the video is blocked.
-    if (Controls()) {
-      NotifyUAWidgetSetupOrChange();
-    }
-#endif
   }
 
   mUnboundFromTree = false;

dom/media/test/test_cloneElementVisually_no_suspend.html

@@ -56,7 +56,11 @@ add_task(async () => {
       suspendTimerFired = true;
     }
     originalVideo.addEventListener("mozstartvideosuspendtimer", listener);
-    originalVideo.setVisible(false);
+
+    // Have to do this to access normally-preffed off binding methods for some
+    // reason.
+    // See bug 1544257.
+    SpecialPowers.wrap(originalVideo).setVisible(false);
 
     await waitForEventOnce(originalVideo, "ended");
 
@@ -65,7 +69,10 @@ add_task(async () => {
     ok(!suspendTimerFired,
        "mozstartvideosuspendtimer should not have fired.");
 
-    originalVideo.setVisible(true);
+    // Have to do this to access normally-preffed off binding methods for some
+    // reason.
+    // See bug 1544257.
+    SpecialPowers.wrap(originalVideo).setVisible(true);
   });
 
   await originalVideo.play();

dom/media/tests/mochitest/test_setSinkId.html

@@ -30,6 +30,11 @@
     info(`Found  ${audioDevices.length} output devices`);
     ok(audioDevices.length > 0, "More than one output device found");
 
+    // Have to do this to access normally-preffed off binding methods for some
+    // reason.
+    // See bug 1544257.
+    let audio = SpecialPowers.wrap(audio);
+
     is(audio.sinkId, "", "Initial value is empty string");
 
     const p = audio.setSinkId(audioDevices[0].deviceId);