Backed out changeset 942b01866756 (bug 1295844) for xp mda failures a=backout

dom/media/test/gizmo-noaudio.webm^headers^

@@ -1 +0,0 @@
-Cache-Control: no-store

dom/media/test/gizmo.webm^headers^

@@ -1 +0,0 @@
-Cache-Control: no-store

dom/media/test/manifest.js

@@ -1414,9 +1414,7 @@ var gEMENonMSEFailTests = [
 // background tabs tests.
 var gDecodeSuspendTests = [
   { name:"gizmo.mp4", type:"video/mp4", duration:5.56 },
-  { name:"gizmo-noaudio.mp4", type:"video/mp4", duration:5.56 },
-  { name:"gizmo.webm", type:'video/webm; codecs="vp9,opus"', duration:5.56 },
-  { name:"gizmo-noaudio.webm", type:'video/webm; codecs="vp9"', duration:5.56 }
+  { name:"gizmo-noaudio.mp4", type:"video/mp4", duration:5.56 }
 ];
 
 function checkMetadata(msg, e, test) {

dom/media/test/mochitest.ini

@@ -417,10 +417,6 @@ support-files =
   gizmo.mp4^headers^
   gizmo-noaudio.mp4
   gizmo-noaudio.mp4^headers^
-  gizmo.webm
-  gizmo.webm^headers^
-  gizmo-noaudio.webm
-  gizmo-noaudio.webm^headers^
   huge-id3.mp3
   huge-id3.mp3^headers^
   id3tags.mp3