Hide overlay play button if it can't be shown without clipping

third_party/WebKit/Source/core/css/mediaControlsAndroid.css

 /*
  * Copyright (C) 2015 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 17 matching lines @@
 
 audio {
     height: 48px;
 }
 
 audio::-webkit-media-controls-enclosure, video::-webkit-media-controls-enclosure {
     height: 48px;
 }
 
 audio::-webkit-media-controls-panel, video::-webkit-media-controls-panel {
+    /* If this changes, it must also be changed in
+     * core/html/shadow/MediaControls.cpp. */
     height: 48px;
     min-width: 48px;
     line-height: 48px;
     font-size: 14px;
 }
 
 video::-internal-media-controls-overlay-cast-button {
     width: 48px;
     height: 48px;
 }
@@ skipping 14 matching lines @@
 audio::-webkit-media-controls-mute-button, video::-webkit-media-controls-mute-button,
 audio::-webkit-media-controls-fullscreen-button, video::-webkit-media-controls-fullscreen-button,
 audio::-internal-media-controls-cast-button, video::-internal-media-controls-cast-button,
 audio::-internal-media-controls-download-button, video::-internal-media-controls-download-button,
 audio::-internal-media-controls-overflow-button, video::-internal-media-controls-overflow-button,
 video::-webkit-media-controls-toggle-closed-captions-button {
     padding: 8px;
     width: 48px;
     height: 48px;
 }