Bug 1504062 - fix timeouts in dom test_fullscreen_api.html, r=kats

Differential Revision: https://phabricator.services.mozilla.com/D10723

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

dom/html/test/file_fullscreen-featurePolicy-inner.html

@@ -10,14 +10,17 @@ function doRequestFullscreen() {
     document.removeEventListener("fullscreenchange", handler);
     document.removeEventListener("fullscreenerror", handler);
     if (evt.type == "fullscreenchange") {
+      document.addEventListener("fullscreenchange", () => parent.continueTest(evt.type), {once: true});
       document.exitFullscreen();
-    }
+    } else {
       parent.continueTest(evt.type);
     }
+  }
   parent.ok(document.fullscreenEnabled, "Fullscreen " +
             `should be enabled in ${parent.testTargetName}`);
   document.addEventListener("fullscreenchange", handler);
   document.addEventListener("fullscreenerror", handler);
+  parent.opener.info("Requesting fullscreen");
   document.documentElement.requestFullscreen();
 }
 </script>

dom/html/test/file_fullscreen-featurePolicy.html

@@ -55,6 +55,7 @@ function nextTest() {
   }
 
   let test = tests.shift();
+  opener.info("Running " + test[0]);
 
   // Create an iframe with an allowfullscreen and with an allow attribute.
   // The request should be denied or allowed, based on the current test.

dom/html/test/mochitest.ini

@@ -437,7 +437,7 @@ skip-if = toolkit == 'android'
 [test_formelements.html]
 [test_fullscreen-api.html]
 tags = fullscreen
-skip-if = toolkit == 'android' || (os == 'linux' && !debug) # linux opt/pgo timeouts: bug 1504062
+skip-if = toolkit == 'android'
 support-files =
   file_fullscreen-api.html
   file_fullscreen-backdrop.html

dom/html/test/test_fullscreen-api.html

@@ -60,9 +60,15 @@ function finish() {
 
 function nextTest() {
   if (testWindow) {
-    testWindow.close();
+    info("Waiting for focus to return to main window");
-  }
+    window.addEventListener("focus", function() {
+      info("main window focused, starting next test");
       SimpleTest.executeSoon(runNextTest);
+    }, {once: true});
+    testWindow.close();
+  } else {
+    SimpleTest.executeSoon(runNextTest);
+  }
 }
 
 var gHeadlessSkipList = [
@@ -130,10 +136,12 @@ function runNextTest() {
         waitForLoadAndPaint(testWindow, function() {
           SimpleTest.waitForFocus(function() {
             SimpleTest.waitForFocus(function() {
+              info("Were focused");
               // For the platforms that support reporting occlusion state (e.g. Mac),
               // we should wait until the docshell has been activated again,
               // otherwise, the fullscreen request might be denied.
               if (testWindow.document.hidden) {
+                info("Waiting for document to unhide");
                 waitForEvent(testWindow.document, "visibilitychange", (event) => {
                   return !testWindow.document.hidden;
                 }, testWindow.begin);