Sync snap-to-lines VTT cue layout steps with spec

LayoutTests/media/track/track-cue-rendering-line-doesnt-fit-expected.html

Index: LayoutTests/media/track/track-cue-rendering-line-doesnt-fit-expected.html
diff --git a/LayoutTests/media/track/track-cue-rendering-position-auto-expected.html b/LayoutTests/media/track/track-cue-rendering-line-doesnt-fit-expected.html
similarity index 52%
copy from LayoutTests/media/track/track-cue-rendering-position-auto-expected.html
copy to LayoutTests/media/track/track-cue-rendering-line-doesnt-fit-expected.html
index 40ba31560545441d951e6dd12e42ccb0eaca6ec8..53e7d2863d76541982339001bdbcffd47d521a58 100644
--- a/LayoutTests/media/track/track-cue-rendering-position-auto-expected.html
+++ b/LayoutTests/media/track/track-cue-rendering-line-doesnt-fit-expected.html
@@ -20,29 +20,17 @@ var mediaFile = findMediaFile('video', '../content/test');
 .cue.start {
     text-align: start;
 }
-.cue.middle {
-    text-align: center;
-}
-.cue.end {
-    text-align: end;
-}
 .cue > span {
     font-family: sans-serif;
     background: green;
     color: green;
-    font-size: 50px;
+    font-size: 120px;
     padding: 2px;
 }
 </style>
 <div class="container">
   <video><script>document.currentScript.parentNode.src = mediaFile;</script></video>
-  <div class=video><div class="cue start"><span>XXX</span></div></div>
-</div>
-<div class="container">
-  <video><script>document.currentScript.parentNode.src = mediaFile;</script></video>
-  <div class=video><div class="cue middle"><span>XXX</span></div></div>
-</div>
-<div class="container">
-  <video><script>document.currentScript.parentNode.src = mediaFile;</script></video>
-  <div class=video><div class="cue end"><span>XXX</span></div></div>
+  <div class=video>
+    <div class="cue start"><span>PAS</span></div>
+  </div>
 </div>