Bug 1396232 - enable prefs needed for orientation lock test. r=ralin

Also, use |run-if| instead of |skip-if| to filter the test.

MozReview-Commit-ID: 5NUoSoRzqMC

--HG--
extra : rebase_source : c50eb0cf377d02456089382108a49658ea6930b7

toolkit/content/tests/widgets/mochitest.ini

@@ -50,4 +50,4 @@ skip-if = toolkit == 'android'
 [test_bug898940.html]
 [test_videocontrols_error.html]
 [test_videocontrols_orientation.html]
-skip-if = toolkit != 'android'
+run-if = toolkit == 'android'

toolkit/content/tests/widgets/test_videocontrols_orientation.html

@@ -21,7 +21,9 @@ var video = document.getElementById("video");
 
 let onLoaded = event => {
   SpecialPowers.pushPrefEnv(
-    {"set": [["full-screen-api.allow-trusted-requests-only", false]]},
+    {"set": [["full-screen-api.allow-trusted-requests-only", false],
+             ["full-screen-api.unprefix.enabled", true],
+             ["media.videocontrols.lock-video-orientation", true]]},
     startMediaLoad);
 }
 window.addEventListener("load", onLoaded);