--- a/dom/media/tests/mochitest/mochitest.ini
+++ b/dom/media/tests/mochitest/mochitest.ini
@@ -19,16 +19,22 @@ support-files =
   !/dom/canvas/test/webgl-mochitest/webgl-util.js
   !/dom/media/test/manifest.js
   !/dom/media/test/320x240.ogv
   !/dom/media/test/r11025_s16_c1.wav
   !/dom/media/test/bug461281.ogg
   !/dom/media/test/seek.webm
   !/dom/media/test/gizmo.mp4
 
+# MediaManager and/or MediaDevices objects were not GCed after
+# previous tests, which make this test unable to detect bug 1423515
+# Before we find out a way to clean up backends when they're no longer used,
+# move the test to the front.
+[test_ondevicechange.html]
+skip-if = os == 'android'
 [test_a_noOp.html]
 [test_dataChannel_basicAudio.html]
 skip-if = (android_version == '18') # Bug 962984 for debug, bug 963244 for opt
 [test_dataChannel_basicAudioVideo.html]
 skip-if = android_version == '18' # android(Bug 1189784, timeouts on 4.3 emulator)
 [test_dataChannel_basicAudioVideoNoBundle.html]
 skip-if = android_version == '18' # android(Bug 1189784, timeouts on 4.3 emulator)
 [test_dataChannel_basicAudioVideoCombined.html]
@@ -37,18 +43,16 @@ skip-if = toolkit == 'android'  # Bug 11
 [test_dataChannel_basicVideo.html]
 skip-if = android_version == '18' # android(Bug 1189784, timeouts on 4.3 emulator)
 [test_dataChannel_bug1013809.html]
 skip-if = android_version == '18' # android(Bug 1189784, timeouts on 4.3 emulator)
 [test_dataChannel_noOffer.html]
 [test_enumerateDevices.html]
 [test_enumerateDevices_iframe.html]
 skip-if = true # needed by test_enumerateDevices.html on builders
-[test_ondevicechange.html]
-skip-if = os == 'android'
 [test_getUserMedia_active_autoplay.html]
 [test_getUserMedia_audioCapture.html]
 skip-if = toolkit == 'android' # android(Bug 1189784, timeouts on 4.3 emulator), android(Bug 1264333)
 [test_getUserMedia_addTrackRemoveTrack.html]
 skip-if = android_version == '18' || os == 'linux' # android(Bug 1189784, timeouts on 4.3 emulator), linux bug 1377450
 [test_getUserMedia_addtrack_removetrack_events.html]
 skip-if = os == 'linux' && debug # Bug 1389983
 [test_getUserMedia_basicAudio.html]