fix: Mux-player childList observer behavior

examples/vanilla-ts-esm/public/mux-player.html

@@ -43,7 +43,10 @@ <h2>On-demand</h2>
     <mux-player
       stream-type="on-demand"
       playback-id="Sc89iWAyNkhJ3P1rQ02nrEdCFTnfT01CZ2KmaEcxXfB008"
-    ></mux-player>
+    >
+      <track label="Japanese" kind="captions" srclang="ja" src="./vtt/elephantsdream/captions.ja.vtt"></track>
+      <track default kind="chapters" src="./vtt/elephantsdream/chapters.vtt"></track>
+    </mux-player>
 
     <button id="load-new-playback-id">Load new playback id</button>
     <script>

examples/vanilla-ts-esm/public/vtt/elephantsdream/captions.ja.vtt

@@ -0,0 +1,326 @@
+WEBVTT
+
+1
+00:00:15.042 --> 00:00:18.042
+左に見えるのは…
+
+2
+00:00:18.750 --> 00:00:20.333
+右に見えるのは…
+
+3
+00:00:20.417 --> 00:00:21.917
+…首刈り機
+
+4
+00:00:22.000 --> 00:00:24.625
+すべて安全
+完璧に安全だ
+
+5
+00:00:26.333 --> 00:00:27.333
+イーモ？
+
+6
+00:00:28.875 --> 00:00:30.250
+危ない！
+
+7
+00:00:47.125 --> 00:00:48.250
+ケガはないか？
+
+8
+00:00:51.917 --> 00:00:53.917
+ええ、多分…
+あなたは？
+
+9
+00:00:55.625 --> 00:00:57.125
+わしは平気だ
+
+10
+00:00:57.583 --> 00:01:01.667
+起きてくれイーモ
+ここは危ない
+
+11
+00:01:02.208 --> 00:01:03.667
+行こう
+
+12
+00:01:03.750 --> 00:01:04.917
+どこに？
+
+13
+00:01:05.875 --> 00:01:07.875
+すぐにわかるさ！
+
+14
+00:01:16.167 --> 00:01:18.375
+イーモ、こっちだ
+
+15
+00:01:34.958 --> 00:01:36.958
+ついて来るんだ！
+
+16
+00:02:11.583 --> 00:02:12.792
+イーモ、早く！
+
+17
+00:02:48.375 --> 00:02:50.083
+むやみにさわるな！
+
+18
+00:02:50.750 --> 00:02:54.500
+僕はただ、電話に
+…出ようと
+
+19
+00:02:55.000 --> 00:02:58.208
+イーモ、見るんだ…
+いや、聞いてくれ
+
+20
+00:02:59.750 --> 00:03:02.292
+君は「聞き方」を知る必要がある
+
+21
+00:03:03.625 --> 00:03:05.125
+これは遊びじゃない
+
+22
+00:03:06.167 --> 00:03:10.417
+我々はここでは
+たやすく死ぬ
+
+23
+00:03:11.208 --> 00:03:14.125
+機械の声を聞くんだ
+
+24
+00:03:18.333 --> 00:03:22.417
+君の息づかいを聞くんだ
+
+25
+00:04:27.208 --> 00:04:29.250
+そんなことして疲れない？
+
+26
+00:04:29.583 --> 00:04:31.083
+疲れる?!
+
+27
+00:04:31.750 --> 00:04:34.667
+この機械は非常に正確で
+
+28
+00:04:35.500 --> 00:04:37.708
+一つ間違えば…
+
+29
+00:04:37.833 --> 00:04:40.792
+…地面に落ちてバラバラだ
+
+30
+00:04:41.042 --> 00:04:42.375
+え、でも―
+
+31
+00:04:42.417 --> 00:04:46.542
+バラバラだぞ、イーモ！
+それでいいのか？
+
+32
+00:04:48.083 --> 00:04:50.000
+バラバラで死ぬんだぞ？
+
+33
+00:04:50.583 --> 00:04:52.250
+バラバラだ！
+
+34
+00:05:41.833 --> 00:05:43.458
+イーモ、目を閉じるんだ
+
+35
+00:05:44.917 --> 00:05:46.583
+なぜ？
+―早く！
+
+36
+00:05:53.750 --> 00:05:56.042
+それでいい
+
+37
+00:05:59.542 --> 00:06:03.792
+左に見えるものは何だ、イーモ？
+
+38
+00:06:04.417 --> 00:06:06.000
+え…何も
+―本当か？
+
+39
+00:06:06.333 --> 00:06:07.917
+全く何も
+
+40
+00:06:08.042 --> 00:06:12.833
+では右は
+何か見えるか、イーモ？
+
+41
+00:06:13.875 --> 00:06:16.917
+同じだよプルーグ、全く同じ…
+
+42
+00:06:17.083 --> 00:06:18.583
+何もない！
+
+43
+00:06:40.625 --> 00:06:43.208
+プルーグ！何か聞こえない？
+
+44
+00:06:43.625 --> 00:06:45.042
+あそこに行かないか？
+
+45
+00:06:45.208 --> 00:06:48.042
+あそこ？
+…安全じゃない
+
+46
+00:06:49.917 --> 00:06:52.500
+でも…
+―本当に危ないぞ
+
+47
+00:06:53.292 --> 00:06:54.792
+大丈夫だよ…
+
+48
+00:06:54.833 --> 00:06:56.333
+だめだ
+
+49
+00:06:57.667 --> 00:07:00.167
+だめだ！
+
+50
+00:07:00.875 --> 00:07:03.750
+まだ続ける気か、イーモ？
+
+51
+00:07:04.250 --> 00:07:05.917
+いいえ…
+
+52
+00:07:09.458 --> 00:07:10.833
+イーモ？
+
+53
+00:07:11.875 --> 00:07:13.542
+イーモ、なぜ…
+
+54
+00:07:13.583 --> 00:07:14.458
+イーモ…
+
+55
+00:07:14.500 --> 00:07:18.500
+…なぜここの美しさが
+見えない？
+
+56
+00:07:18.833 --> 00:07:20.750
+仕組みがこんなに…
+
+57
+00:07:20.875 --> 00:07:24.000
+こんなに完全なのに
+
+58
+00:07:24.083 --> 00:07:27.417
+もういいよ！プルーグ！
+
+59
+00:07:27.542 --> 00:07:30.333
+そこには何もないんだから
+
+60
+00:07:31.500 --> 00:07:35.333
+なぜ命を「ない」物に
+ゆだねなきゃ？
+
+61
+00:07:35.583 --> 00:07:37.125
+教えてくれないか？
+
+62
+00:07:37.500 --> 00:07:39.167
+さあ！
+
+63
+00:07:43.208 --> 00:07:44.583
+プルーグ…
+
+64
+00:07:45.500 --> 00:07:47.333
+あなたは病気なんだ
+
+65
+00:07:47.375 --> 00:07:49.208
+僕から離れてくれ
+
+66
+00:07:52.583 --> 00:07:55.083
+いかん！イーモ！ワナだ！
+
+67
+00:07:55.833 --> 00:07:57.167
+ワナだ？ ふーん
+
+68
+00:07:57.208 --> 00:08:01.750
+左に何が見える？
+バビロンの空中庭園！
+
+69
+00:08:02.250 --> 00:08:04.292
+これがワナとでも？
+
+70
+00:08:05.458 --> 00:08:07.125
+だめだ、イーモ
+
+71
+00:08:09.417 --> 00:08:12.792
+右にあるのは…
+…すごい！…
+
+72
+00:08:13.000 --> 00:08:14.750
+…ロードス島の巨像だ！
+
+73
+00:08:15.833 --> 00:08:16.708
+やめろ！
+
+74
+00:08:16.750 --> 00:08:22.167
+この巨像はあなたの物
+プルーグ、あなたのだよ
+
+75
+00:08:51.333 --> 00:08:53.167
+いってるじゃないか…
+
+76
+00:08:53.208 --> 00:08:55.500
+そこにあるって、イーモ…
+
+77
+00:08:57.333 --> 00:09:00.000
+…あるって

examples/vanilla-ts-esm/public/vtt/elephantsdream/chapters.vtt

@@ -0,0 +1,43 @@
+WEBVTT
+
+NOTE Created by Owen Edwards 2015. http://creativecommons.org/licenses/by/2.5/
+NOTE Based on 'finalbreakdown.rtf', part of the prepoduction notes, which are:
+NOTE (c) Copyright 2006, Blender Foundation /
+NOTE                     Netherlands Media Art Institute /
+NOTE                     www.elephantsdream.org
+
+1
+00:00:00.000 --> 00:00:27.500
+Prologue
+
+2
+00:00:27.500 --> 00:01:10.000
+Switchboard trap
+
+3
+00:01:10.000 --> 00:03:00.000
+Telephone/Lecture
+
+4
+00:03:25.000 --> 00:04:52.000
+Typewriter
+
+5
+00:04:52.000 --> 00:06:19.500
+Proog shows Emo stuff and some extra text for testing
+
+6
+00:06:19.500 --> 00:07:09.000
+Which way
+
+7
+00:07:09.000 --> 00:07:45.000
+Emo flips out
+
+8
+00:07:45.000 --> 00:09:25.000
+Emo creates
+
+9
+00:09:25.000 --> 00:10:54.998
+Closing credits

packages/mux-player/src/template.ts

@@ -137,6 +137,7 @@ export const content = (props: MuxTemplateProps) => html`
       ${props.storyboard
         ? html`<track label="thumbnails" default kind="metadata" src="${props.storyboard}" />`
         : html``}
+      <slot></slot>
     </mux-video>
     <slot name="poster" slot="poster">
       <media-poster-image