Bug 1476975 - P2. Add mochitests. r=dminor

--HG--
extra : rebase_source : a24191c0bc355b69d425291a0ebdea21d962866a

dom/media/test/can_play_type_webm.js

@@ -1,6 +1,6 @@
-function check_webm(v, enabled) {
+async function check_webm(v, enabled) {
   function check(type, expected) {
-    is(v.canPlayType(type), enabled ? expected : "", type);
+    is(v.canPlayType(type), enabled ? expected : "", type + "='" + expected + "'");
   }
 
   // WebM types
@@ -26,4 +26,31 @@ function check_webm(v, enabled) {
   check("video/webm; codecs=xyz", "");
   check("video/webm; codecs=xyz,vorbis", "");
   check("video/webm; codecs=vorbis,xyz", "");
+
+  function getPref(name) {
+    var pref = false;
+    try {
+      pref = SpecialPowers.getBoolPref(name);
+    } catch(ex) { }
+    return pref;
+  }
+
+  function isWindows32() {
+    return navigator.userAgent.includes("Windows") &&
+           !navigator.userAgent.includes("Win64");
+  }
+
+  function isAndroid() {
+    return navigator.userAgent.includes("Android");
+  }
+
+  const haveAv1 = getPref("media.av1.enabled");
+  check("video/webm; codecs=\"av1\"", haveAv1 ? "probably" : "");
+
+  await SpecialPowers.pushPrefEnv({"set": [["media.av1.enabled", true]]});
+  // AV1 is disabled on Windows 32 bits (bug 1475564) and Android (bug 1368843)
+  check("video/webm; codecs=\"av1\"", (isWindows32() || isAndroid()) ? "" : "probably");
+
+  await SpecialPowers.pushPrefEnv({"set": [["media.av1.enabled", false]]});
+  check("video/webm; codecs=\"av1\"", "");
 }

dom/media/test/test_can_play_type_mpeg.html

@@ -96,6 +96,9 @@ function check_mp4(v, enabled) {
     check(codec, "probably");
     ok(MediaSource.isTypeSupported(codec), "VP9 in MP4 should be supported in MSE");
   });
+
+  // AV1 (disabled until bug 1417050 is fixed)
+  check("video/mp4; codecs=\"av1\"", "");
 }
 
 function check_mp3(v, enabled) {

dom/media/test/test_can_play_type_webm.html

@@ -21,8 +21,18 @@ a Bug 566245</a>
 <pre id="test">
 <script src="can_play_type_webm.js"></script>
 <script>
-check_webm(document.getElementById('v'), true);
-mediaTestCleanup();
+  async function runTest() {
+    try {
+      await check_webm(document.getElementById('v'), true);
+      mediaTestCleanup();
+    } catch (e) {
+      info("Exception " + e.message);
+      ok(false, "Threw exception " + e.message);
+    }
+    SimpleTest.finish();
+  }
+  SimpleTest.waitForExplicitFinish();
+  addLoadEvent(runTest);
 </script>
 </pre>
 </body>