Separate the text track container from the media controls

Source/core/css/mediaControls.css

 /*
  * Copyright (C) 2009 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 326 matching lines @@
 audio::-webkit-media-controls-fullscreen-volume-min-button, video::-webkit-media-controls-fullscreen-volume-min-button {
     display: none;
 }
 
 audio::-webkit-media-controls-fullscreen-volume-max-button, video::-webkit-media-controls-fullscreen-volume-max-button {
     display: none;
 }
 
 video::-webkit-media-text-track-container {
     position: relative;
-    width: 100%;
+    width: inherit;
+    height: inherit;
     overflow: hidden;
-    padding-bottom: 5px;
 
     font: 22px sans-serif;
     text-align: center;
     color: rgba(255, 255, 255, 1);
 
     letter-spacing: normal;
     word-spacing: normal;
     text-transform: none;
     text-indent: 0;
     text-decoration: none;
     pointer-events: none;
     -webkit-user-select: none;
     word-break: break-word;
-
-    flex: 1 1;
 }
 
 video::cue {
     display: inline;
 
     background-color: rgba(0, 0, 0, 0.8);
     padding: 2px 2px;
 }
 
 video::-webkit-media-text-track-region {
@@ skipping 36 matching lines @@
     font-weight: bold;
 }
 
 video::-webkit-media-text-track-container u {
     text-decoration: underline;
 }
 
 video::-webkit-media-text-track-container i {
     font-style: italic;
 }