summaryrefslogtreecommitdiffstats
path: root/dom/html/HTMLMediaElement.h
blob: 0d35fcc85c128f9db0a1d49a2d66c0aac3dd5e40 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_HTMLMediaElement_h
#define mozilla_dom_HTMLMediaElement_h

#include "nsGenericHTMLElement.h"
#include "AudioChannelService.h"
#include "MediaEventSource.h"
#include "SeekTarget.h"
#include "MediaDecoderOwner.h"
#include "MediaElementEventRunners.h"
#include "MediaPlaybackDelayPolicy.h"
#include "MediaPromiseDefs.h"
#include "TelemetryProbesReporter.h"
#include "nsCycleCollectionParticipant.h"
#include "Visibility.h"
#include "mozilla/CORSMode.h"
#include "DecoderTraits.h"
#include "mozilla/Attributes.h"
#include "mozilla/StateWatching.h"
#include "mozilla/WeakPtr.h"
#include "mozilla/dom/DecoderDoctorNotificationBinding.h"
#include "mozilla/dom/HTMLMediaElementBinding.h"
#include "mozilla/dom/MediaDebugInfoBinding.h"
#include "mozilla/dom/MediaKeys.h"
#include "mozilla/dom/TextTrackManager.h"
#include "nsGkAtoms.h"
#include "PrincipalChangeObserver.h"
#include "nsStubMutationObserver.h"
#include "MediaSegment.h"  // for PrincipalHandle, GraphTime

#include <utility>

// X.h on Linux #defines CurrentTime as 0L, so we have to #undef it here.
#ifdef CurrentTime
#  undef CurrentTime
#endif

// Define to output information on decoding and painting framerate
/* #define DEBUG_FRAME_RATE 1 */

using nsMediaNetworkState = uint16_t;
using nsMediaReadyState = uint16_t;
using SuspendTypes = uint32_t;
using AudibleChangedReasons = uint32_t;

class nsIStreamListener;

namespace mozilla {
class AbstractThread;
class ChannelMediaDecoder;
class DecoderDoctorDiagnostics;
class DOMMediaStream;
class ErrorResult;
class FirstFrameVideoOutput;
class MediaResource;
class MediaDecoder;
class MediaInputPort;
class MediaTrack;
class MediaTrackGraph;
class MediaStreamWindowCapturer;
struct SharedDummyTrack;
class VideoFrameContainer;
class VideoOutput;
namespace dom {
class HTMLSourceElement;
class MediaKeys;
class TextTrack;
class TimeRanges;
class WakeLock;
class MediaStreamTrack;
class MediaStreamTrackSource;
class MediaTrack;
class VideoStreamTrack;
}  // namespace dom
}  // namespace mozilla

class AudioDeviceInfo;
class nsIChannel;
class nsIHttpChannel;
class nsILoadGroup;
class nsIRunnable;
class nsISerialEventTarget;
class nsITimer;
class nsRange;

namespace mozilla::dom {

// Number of milliseconds between timeupdate events as defined by spec
#define TIMEUPDATE_MS 250

class MediaError;
class MediaSource;
class PlayPromise;
class Promise;
class TextTrackList;
class AudioTrackList;
class VideoTrackList;

enum class StreamCaptureType : uint8_t { CAPTURE_ALL_TRACKS, CAPTURE_AUDIO };

enum class StreamCaptureBehavior : uint8_t {
  CONTINUE_WHEN_ENDED,
  FINISH_WHEN_ENDED
};

class HTMLMediaElement : public nsGenericHTMLElement,
                         public MediaDecoderOwner,
                         public PrincipalChangeObserver<MediaStreamTrack>,
                         public SupportsWeakPtr,
                         public nsStubMutationObserver,
                         public TelemetryProbesReporterOwner {
 public:
  using TimeStamp = mozilla::TimeStamp;
  using ImageContainer = mozilla::layers::ImageContainer;
  using VideoFrameContainer = mozilla::VideoFrameContainer;
  using MediaResource = mozilla::MediaResource;
  using MediaDecoderOwner = mozilla::MediaDecoderOwner;
  using MetadataTags = mozilla::MetadataTags;

  // Helper struct to keep track of the MediaStreams returned by
  // mozCaptureStream(). For each OutputMediaStream, dom::MediaTracks get
  // captured into MediaStreamTracks which get added to
  // OutputMediaStream::mStream.
  struct OutputMediaStream {
    OutputMediaStream(RefPtr<DOMMediaStream> aStream, bool aCapturingAudioOnly,
                      bool aFinishWhenEnded);
    ~OutputMediaStream();

    RefPtr<DOMMediaStream> mStream;
    nsTArray<RefPtr<MediaStreamTrack>> mLiveTracks;
    const bool mCapturingAudioOnly;
    const bool mFinishWhenEnded;
    // If mFinishWhenEnded is true, this is the URI of the first resource
    // mStream got tracks for.
    nsCOMPtr<nsIURI> mFinishWhenEndedLoadingSrc;
    // If mFinishWhenEnded is true, this is the first MediaStream mStream got
    // tracks for.
    RefPtr<DOMMediaStream> mFinishWhenEndedAttrStream;
    // If mFinishWhenEnded is true, this is the MediaSource being played.
    RefPtr<MediaSource> mFinishWhenEndedMediaSource;
  };

  NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED

  CORSMode GetCORSMode() { return mCORSMode; }

  explicit HTMLMediaElement(
      already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo);
  void Init();

  // `eMandatory`: `timeupdate` occurs according to the spec requirement.
  // Eg.
  // https://html.spec.whatwg.org/multipage/media.html#seeking:event-media-timeupdate
  // `ePeriodic` : `timeupdate` occurs regularly and should follow the rule
  // of not dispatching that event within 250 ms. Eg.
  // https://html.spec.whatwg.org/multipage/media.html#offsets-into-the-media-resource:event-media-timeupdate
  enum class TimeupdateType : bool {
    eMandatory = false,
    ePeriodic = true,
  };

  // This is used for event runner creation. Currently only timeupdate needs
  // that, but it can be used to extend for other events in the future if
  // necessary.
  enum class EventFlag : uint8_t {
    eNone = 0,
    eMandatory = 1,
  };

  /**
   * This is used when the browser is constructing a video element to play
   * a channel that we've already started loading. The src attribute and
   * <source> children are ignored.
   * @param aChannel the channel to use
   * @param aListener returns a stream listener that should receive
   * notifications for the stream
   */
  nsresult LoadWithChannel(nsIChannel* aChannel, nsIStreamListener** aListener);

  // nsISupports
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(HTMLMediaElement,
                                           nsGenericHTMLElement)
  NS_IMPL_FROMNODE_HELPER(HTMLMediaElement,
                          IsAnyOfHTMLElements(nsGkAtoms::video,
                                              nsGkAtoms::audio))

  NS_DECL_ADDSIZEOFEXCLUDINGTHIS

  // EventTarget
  void GetEventTargetParent(EventChainPreVisitor& aVisitor) override;

  void NodeInfoChanged(Document* aOldDoc) override;

  virtual bool ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
                              const nsAString& aValue,
                              nsIPrincipal* aMaybeScriptedPrincipal,
                              nsAttrValue& aResult) override;

  virtual nsresult BindToTree(BindContext&, nsINode& aParent) override;
  virtual void UnbindFromTree(bool aNullParent = true) override;
  virtual void DoneCreatingElement() override;

  virtual bool IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
                               int32_t* aTabIndex) override;
  virtual int32_t TabIndexDefault() override;

  // Called by the video decoder object, on the main thread,
  // when it has read the metadata containing video dimensions,
  // etc.
  virtual void MetadataLoaded(const MediaInfo* aInfo,
                              UniquePtr<const MetadataTags> aTags) final;

  // Called by the decoder object, on the main thread,
  // when it has read the first frame of the video or audio.
  void FirstFrameLoaded() final;

  // Called by the video decoder object, on the main thread,
  // when the resource has a network error during loading.
  void NetworkError(const MediaResult& aError) final;

  // Called by the video decoder object, on the main thread, when the
  // resource has a decode error during metadata loading or decoding.
  void DecodeError(const MediaResult& aError) final;

  // Called by the decoder object, on the main thread, when the
  // resource has a decode issue during metadata loading or decoding, but can
  // continue decoding.
  void DecodeWarning(const MediaResult& aError) final;

  // Return true if error attribute is not null.
  bool HasError() const final;

  // Called by the video decoder object, on the main thread, when the
  // resource load has been cancelled.
  void LoadAborted() final;

  // Called by the video decoder object, on the main thread,
  // when the video playback has ended.
  void PlaybackEnded() final;

  // Called by the video decoder object, on the main thread,
  // when the resource has started seeking.
  void SeekStarted() final;

  // Called by the video decoder object, on the main thread,
  // when the resource has completed seeking.
  void SeekCompleted() final;

  // Called by the video decoder object, on the main thread,
  // when the resource has aborted seeking.
  void SeekAborted() final;

  // Called by the media stream, on the main thread, when the download
  // has been suspended by the cache or because the element itself
  // asked the decoder to suspend the download.
  void DownloadSuspended() final;

  // Called by the media stream, on the main thread, when the download
  // has been resumed by the cache or because the element itself
  // asked the decoder to resumed the download.
  void DownloadResumed();

  // Called to indicate the download is progressing.
  void DownloadProgressed() final;

  // Called by the media decoder to indicate whether the media cache has
  // suspended the channel.
  void NotifySuspendedByCache(bool aSuspendedByCache) final;

  // Return true if the media element is actually invisible to users.
  bool IsActuallyInvisible() const override;

  // Return true if the element is in the view port.
  bool IsInViewPort() const;

  // Called by the media decoder and the video frame to get the
  // ImageContainer containing the video data.
  VideoFrameContainer* GetVideoFrameContainer() final;
  layers::ImageContainer* GetImageContainer();

  /**
   * Call this to reevaluate whether we should start/stop due to our owner
   * document being active, inactive, visible or hidden.
   */
  void NotifyOwnerDocumentActivityChanged();

  // Called when the media element enters or leaves the fullscreen.
  void NotifyFullScreenChanged();

  bool IsInFullScreen() const;

  // From PrincipalChangeObserver<MediaStreamTrack>.
  void PrincipalChanged(MediaStreamTrack* aTrack) override;

  void UpdateSrcStreamVideoPrincipal(const PrincipalHandle& aPrincipalHandle);

  // Called after the MediaStream we're playing rendered a frame to aContainer
  // with a different principalHandle than the previous frame.
  void PrincipalHandleChangedForVideoFrameContainer(
      VideoFrameContainer* aContainer,
      const PrincipalHandle& aNewPrincipalHandle) override;

  // Dispatch events
  void DispatchAsyncEvent(const nsAString& aName) final;
  void DispatchAsyncEvent(RefPtr<nsMediaEventRunner> aRunner);

  // Triggers a recomputation of readyState.
  void UpdateReadyState() override {
    mWatchManager.ManualNotify(&HTMLMediaElement::UpdateReadyStateInternal);
  }

  // Dispatch events that were raised while in the bfcache
  nsresult DispatchPendingMediaEvents();

  // Return true if we can activate autoplay assuming enough data has arrived.
  // https://html.spec.whatwg.org/multipage/media.html#eligible-for-autoplay
  bool IsEligibleForAutoplay();

  // Notify that state has changed that might cause an autoplay element to
  // start playing.
  // If the element is 'autoplay' and is ready to play back (not paused,
  // autoplay pref enabled, etc), it should start playing back.
  void CheckAutoplayDataReady();

  void RunAutoplay();

  // Check if the media element had crossorigin set when loading started
  bool ShouldCheckAllowOrigin();

  // Returns true if the currently loaded resource is CORS same-origin with
  // respect to the document.
  bool IsCORSSameOrigin();

  // Is the media element potentially playing as defined by the HTML 5
  // specification.
  // http://www.whatwg.org/specs/web-apps/current-work/#potentially-playing
  bool IsPotentiallyPlaying() const;

  // Has playback ended as defined by the HTML 5 specification.
  // http://www.whatwg.org/specs/web-apps/current-work/#ended
  bool IsPlaybackEnded() const;

  // principal of the currently playing resource. Anything accessing the
  // contents of this element must have a principal that subsumes this
  // principal. Returns null if nothing is playing.
  already_AddRefed<nsIPrincipal> GetCurrentPrincipal();

  // Return true if the loading of this resource required cross-origin
  // redirects.
  bool HadCrossOriginRedirects();

  bool ShouldResistFingerprinting(RFPTarget aTarget) const override;

  // Principal of the currently playing video resource. Anything accessing the
  // image container of this element must have a principal that subsumes this
  // principal. If there are no live video tracks but content has been rendered
  // to the image container, we return the last video principal we had. Should
  // the image container be empty with no live video tracks, we return nullptr.
  already_AddRefed<nsIPrincipal> GetCurrentVideoPrincipal();

  // called to notify that the principal of the decoder's media resource has
  // changed.
  void NotifyDecoderPrincipalChanged() final;

  void GetEMEInfo(dom::EMEDebugInfo& aInfo);

  // Update the visual size of the media. Called from the decoder on the
  // main thread when/if the size changes.
  virtual void UpdateMediaSize(const nsIntSize& aSize);

  void Invalidate(ImageSizeChanged aImageSizeChanged,
                  const Maybe<nsIntSize>& aNewIntrinsicSize,
                  ForceInvalidate aForceInvalidate) override;

  // Returns the CanPlayStatus indicating if we can handle the
  // full MIME type including the optional codecs parameter.
  static CanPlayStatus GetCanPlay(const nsAString& aType,
                                  DecoderDoctorDiagnostics* aDiagnostics);

  /**
   * Called when a child source element is added to this media element. This
   * may queue a task to run the select resource algorithm if appropriate.
   */
  void NotifyAddedSource();

  /**
   * Called when there's been an error fetching the resource. This decides
   * whether it's appropriate to fire an error event.
   */
  void NotifyLoadError(const nsACString& aErrorDetails = nsCString());

  /**
   * Called by one of our associated MediaTrackLists (audio/video) when a
   * MediaTrack is added.
   */
  void NotifyMediaTrackAdded(dom::MediaTrack* aTrack);

  /**
   * Called by one of our associated MediaTrackLists (audio/video) when a
   * MediaTrack is removed.
   */
  void NotifyMediaTrackRemoved(dom::MediaTrack* aTrack);

  /**
   * Called by one of our associated MediaTrackLists (audio/video) when an
   * AudioTrack is enabled or a VideoTrack is selected.
   */
  void NotifyMediaTrackEnabled(dom::MediaTrack* aTrack);

  /**
   * Called by one of our associated MediaTrackLists (audio/video) when an
   * AudioTrack is disabled or a VideoTrack is unselected.
   */
  void NotifyMediaTrackDisabled(dom::MediaTrack* aTrack);

  /**
   * Returns the current load ID. Asynchronous events store the ID that was
   * current when they were enqueued, and if it has changed when they come to
   * fire, they consider themselves cancelled, and don't fire.
   */
  uint32_t GetCurrentLoadID() const { return mCurrentLoadID; }

  /**
   * Returns the load group for this media element's owner document.
   * XXX XBL2 issue.
   */
  already_AddRefed<nsILoadGroup> GetDocumentLoadGroup();

  /**
   * Returns true if the media has played or completed a seek.
   * Used by video frame to determine whether to paint the poster.
   */
  bool GetPlayedOrSeeked() const { return mHasPlayedOrSeeked; }

  nsresult CopyInnerTo(Element* aDest);

  /**
   * Sets the Accept header on the HTTP channel to the required
   * video or audio MIME types.
   */
  virtual nsresult SetAcceptHeader(nsIHttpChannel* aChannel) = 0;

  /**
   * Sets the required request headers on the HTTP channel for
   * video or audio requests.
   */
  void SetRequestHeaders(nsIHttpChannel* aChannel);

  /**
   * Asynchronously awaits a stable state, whereupon aRunnable runs on the main
   * thread. This adds an event which run aRunnable to the appshell's list of
   * sections synchronous the next time control returns to the event loop.
   */
  void RunInStableState(nsIRunnable* aRunnable);

  /**
   * Fires a timeupdate event. If aPeriodic is true, the event will only
   * be fired if we've not fired a timeupdate event (for any reason) in the
   * last 250ms, as required by the spec when the current time is periodically
   * increasing during playback.
   */
  void FireTimeUpdate(TimeupdateType aType);

  void MaybeQueueTimeupdateEvent() final {
    FireTimeUpdate(TimeupdateType::ePeriodic);
  }

  const TimeStamp& LastTimeupdateDispatchTime() const;
  void UpdateLastTimeupdateDispatchTime();

  // WebIDL

  MediaError* GetError() const;

  void GetSrc(nsAString& aSrc) { GetURIAttr(nsGkAtoms::src, nullptr, aSrc); }
  void SetSrc(const nsAString& aSrc, ErrorResult& aError) {
    SetHTMLAttr(nsGkAtoms::src, aSrc, aError);
  }
  void SetSrc(const nsAString& aSrc, nsIPrincipal* aTriggeringPrincipal,
              ErrorResult& aError) {
    SetHTMLAttr(nsGkAtoms::src, aSrc, aTriggeringPrincipal, aError);
  }

  void GetCurrentSrc(nsAString& aCurrentSrc);

  void GetCrossOrigin(nsAString& aResult) {
    // Null for both missing and invalid defaults is ok, since we
    // always parse to an enum value, so we don't need an invalid
    // default, and we _want_ the missing default to be null.
    GetEnumAttr(nsGkAtoms::crossorigin, nullptr, aResult);
  }
  void SetCrossOrigin(const nsAString& aCrossOrigin, ErrorResult& aError) {
    SetOrRemoveNullableStringAttr(nsGkAtoms::crossorigin, aCrossOrigin, aError);
  }

  uint16_t NetworkState() const { return mNetworkState; }

  void NotifyXPCOMShutdown() final;

  // Called by media decoder when the audible state changed or when input is
  // a media stream.
  void SetAudibleState(bool aAudible) final;

  // Notify agent when the MediaElement changes its audible state.
  void NotifyAudioPlaybackChanged(AudibleChangedReasons aReason);

  void GetPreload(nsAString& aValue) {
    if (mSrcAttrStream) {
      nsGkAtoms::none->ToString(aValue);
      return;
    }
    GetEnumAttr(nsGkAtoms::preload, nullptr, aValue);
  }
  void SetPreload(const nsAString& aValue, ErrorResult& aRv) {
    if (mSrcAttrStream) {
      return;
    }
    SetHTMLAttr(nsGkAtoms::preload, aValue, aRv);
  }

  already_AddRefed<TimeRanges> Buffered() const;

  void Load();

  void CanPlayType(const nsAString& aType, nsAString& aResult);

  uint16_t ReadyState() const { return mReadyState; }

  bool Seeking() const;

  double CurrentTime() const;

  void SetCurrentTime(double aCurrentTime, ErrorResult& aRv);
  void SetCurrentTime(double aCurrentTime) {
    SetCurrentTime(aCurrentTime, IgnoreErrors());
  }

  void FastSeek(double aTime, ErrorResult& aRv);

  already_AddRefed<Promise> SeekToNextFrame(ErrorResult& aRv);

  double Duration() const;

  bool HasAudio() const { return mMediaInfo.HasAudio(); }

  virtual bool IsVideo() const { return false; }

  bool HasVideo() const { return mMediaInfo.HasVideo(); }

  bool IsEncrypted() const override { return mIsEncrypted; }

#ifdef MOZ_WMF_CDM
  bool IsUsingWMFCDM() const override;
#endif

  bool Paused() const { return mPaused; }

  double DefaultPlaybackRate() const {
    if (mSrcAttrStream) {
      return 1.0;
    }
    return mDefaultPlaybackRate;
  }

  void SetDefaultPlaybackRate(double aDefaultPlaybackRate, ErrorResult& aRv);

  double PlaybackRate() const {
    if (mSrcAttrStream) {
      return 1.0;
    }
    return mPlaybackRate;
  }

  void SetPlaybackRate(double aPlaybackRate, ErrorResult& aRv);

  already_AddRefed<TimeRanges> Played();

  already_AddRefed<TimeRanges> Seekable() const;

  bool Ended();

  bool Autoplay() const { return GetBoolAttr(nsGkAtoms::autoplay); }

  void SetAutoplay(bool aValue, ErrorResult& aRv) {
    SetHTMLBoolAttr(nsGkAtoms::autoplay, aValue, aRv);
  }

  bool Loop() const { return GetBoolAttr(nsGkAtoms::loop); }

  void SetLoop(bool aValue, ErrorResult& aRv) {
    SetHTMLBoolAttr(nsGkAtoms::loop, aValue, aRv);
  }

  already_AddRefed<Promise> Play(ErrorResult& aRv);
  void Play() {
    IgnoredErrorResult dummy;
    RefPtr<Promise> toBeIgnored = Play(dummy);
  }

  void Pause(ErrorResult& aRv);
  void Pause() { Pause(IgnoreErrors()); }

  bool Controls() const { return GetBoolAttr(nsGkAtoms::controls); }

  void SetControls(bool aValue, ErrorResult& aRv) {
    SetHTMLBoolAttr(nsGkAtoms::controls, aValue, aRv);
  }

  double Volume() const { return mVolume; }

  void SetVolume(double aVolume, ErrorResult& aRv);

  bool Muted() const { return mMuted & MUTED_BY_CONTENT; }
  void SetMuted(bool aMuted);

  bool DefaultMuted() const { return GetBoolAttr(nsGkAtoms::muted); }

  void SetDefaultMuted(bool aMuted, ErrorResult& aRv) {
    SetHTMLBoolAttr(nsGkAtoms::muted, aMuted, aRv);
  }

  bool MozAllowCasting() const { return mAllowCasting; }

  void SetMozAllowCasting(bool aShow) { mAllowCasting = aShow; }

  bool MozIsCasting() const { return mIsCasting; }

  void SetMozIsCasting(bool aShow) { mIsCasting = aShow; }

  // Returns whether a call to Play() would be rejected with NotAllowedError.
  // This assumes "worst case" for unknowns. So if prompting for permission is
  // enabled and no permission is stored, this behaves as if the user would
  // opt to block.
  bool AllowedToPlay() const;

  already_AddRefed<MediaSource> GetMozMediaSourceObject() const;

  // Returns a promise which will be resolved after collecting debugging
  // data from decoder/reader/MDSM. Used for debugging purposes.
  already_AddRefed<Promise> MozRequestDebugInfo(ErrorResult& aRv);

  // Enables DecoderDoctorLogger logging. Used for debugging purposes.
  static void MozEnableDebugLog(const GlobalObject&);

  // Returns a promise which will be resolved after collecting debugging
  // log associated with this element. Used for debugging purposes.
  already_AddRefed<Promise> MozRequestDebugLog(ErrorResult& aRv);

  // For use by mochitests. Enabling pref "media.test.video-suspend"
  void SetVisible(bool aVisible);

  // For use by mochitests. Enabling pref "media.test.video-suspend"
  bool HasSuspendTaint() const;

  // For use by mochitests.
  bool IsVideoDecodingSuspended() const;

  // These functions return accumulated time, which are used for the telemetry
  // usage. Return -1 for error.
  double TotalVideoPlayTime() const;
  double TotalVideoHDRPlayTime() const;
  double VisiblePlayTime() const;
  double InvisiblePlayTime() const;
  double VideoDecodeSuspendedTime() const;
  double TotalAudioPlayTime() const;
  double AudiblePlayTime() const;
  double InaudiblePlayTime() const;
  double MutedPlayTime() const;

  // Test methods for decoder doctor.
  void SetFormatDiagnosticsReportForMimeType(const nsAString& aMimeType,
                                             DecoderDoctorReportType aType);
  void SetDecodeError(const nsAString& aError, ErrorResult& aRv);
  void SetAudioSinkFailedStartup();

  // Synchronously, return the next video frame and mark the element unable to
  // participate in decode suspending.
  //
  // This function is synchronous for cases where decoding has been suspended
  // and JS needs a frame to use in, eg., nsLayoutUtils::SurfaceFromElement()
  // via drawImage().
  already_AddRefed<layers::Image> GetCurrentImage();

  already_AddRefed<DOMMediaStream> GetSrcObject() const;
  void SetSrcObject(DOMMediaStream& aValue);
  void SetSrcObject(DOMMediaStream* aValue);

  bool PreservesPitch() const { return mPreservesPitch; }
  void SetPreservesPitch(bool aPreservesPitch);

  MediaKeys* GetMediaKeys() const;

  already_AddRefed<Promise> SetMediaKeys(MediaKeys* mediaKeys,
                                         ErrorResult& aRv);

  mozilla::dom::EventHandlerNonNull* GetOnencrypted();
  void SetOnencrypted(mozilla::dom::EventHandlerNonNull* aCallback);

  mozilla::dom::EventHandlerNonNull* GetOnwaitingforkey();
  void SetOnwaitingforkey(mozilla::dom::EventHandlerNonNull* aCallback);

  void DispatchEncrypted(const nsTArray<uint8_t>& aInitData,
                         const nsAString& aInitDataType) override;

  bool IsEventAttributeNameInternal(nsAtom* aName) override;

  bool ContainsRestrictedContent() const;

  void NotifyWaitingForKey() override;

  already_AddRefed<DOMMediaStream> CaptureAudio(ErrorResult& aRv,
                                                MediaTrackGraph* aGraph);

  already_AddRefed<DOMMediaStream> MozCaptureStream(ErrorResult& aRv);

  already_AddRefed<DOMMediaStream> MozCaptureStreamUntilEnded(ErrorResult& aRv);

  bool MozAudioCaptured() const { return mAudioCaptured; }

  void MozGetMetadata(JSContext* aCx, JS::MutableHandle<JSObject*> aResult,
                      ErrorResult& aRv);

  double MozFragmentEnd();

  AudioTrackList* AudioTracks();

  VideoTrackList* VideoTracks();

  TextTrackList* GetTextTracks();

  already_AddRefed<TextTrack> AddTextTrack(TextTrackKind aKind,
                                           const nsAString& aLabel,
                                           const nsAString& aLanguage);

  void AddTextTrack(TextTrack* aTextTrack) {
    GetOrCreateTextTrackManager()->AddTextTrack(aTextTrack);
  }

  void RemoveTextTrack(TextTrack* aTextTrack, bool aPendingListOnly = false) {
    if (mTextTrackManager) {
      mTextTrackManager->RemoveTextTrack(aTextTrack, aPendingListOnly);
    }
  }

  void NotifyCueAdded(TextTrackCue& aCue) {
    if (mTextTrackManager) {
      mTextTrackManager->NotifyCueAdded(aCue);
    }
  }
  void NotifyCueRemoved(TextTrackCue& aCue) {
    if (mTextTrackManager) {
      mTextTrackManager->NotifyCueRemoved(aCue);
    }
  }
  void NotifyCueUpdated(TextTrackCue* aCue) {
    if (mTextTrackManager) {
      mTextTrackManager->NotifyCueUpdated(aCue);
    }
  }

  void NotifyCueDisplayStatesChanged();

  bool IsBlessed() const { return mIsBlessed; }

  // A method to check whether we are currently playing.
  bool IsCurrentlyPlaying() const;

  // Returns true if the media element is being destroyed. Used in
  // dormancy checks to prevent dormant processing for an element
  // that will soon be gone.
  bool IsBeingDestroyed();

  virtual void OnVisibilityChange(Visibility aNewVisibility);

  // Begin testing only methods
  float ComputedVolume() const;
  bool ComputedMuted() const;

  // Return true if the media has been suspended media due to an inactive
  // document or prohibiting by the docshell.
  bool IsSuspendedByInactiveDocOrDocShell() const;
  // End testing only methods

  void SetMediaInfo(const MediaInfo& aInfo);
  MediaInfo GetMediaInfo() const override;

  // Gives access to the decoder's frame statistics, if present.
  FrameStatistics* GetFrameStatistics() const override;

  void DispatchAsyncTestingEvent(const nsAString& aName) override;

  AbstractThread* AbstractMainThread() const final;

  // Log the usage of a {visible / invisible} video element as
  // the source of {drawImage(), createPattern(), createImageBitmap() and
  // captureStream()} APIs. This function can be used to collect telemetries for
  // bug 1352007.
  enum class CallerAPI {
    DRAW_IMAGE,
    CREATE_PATTERN,
    CREATE_IMAGEBITMAP,
    CAPTURE_STREAM,
    CREATE_VIDEOFRAME,
  };
  void LogVisibility(CallerAPI aAPI);

  Document* GetDocument() const override;

  already_AddRefed<GMPCrashHelper> CreateGMPCrashHelper() override;

  // Set the sink id (of the output device) that the audio will play. If aSinkId
  // is empty the default device will be set.
  already_AddRefed<Promise> SetSinkId(const nsAString& aSinkId,
                                      ErrorResult& aRv);
  // Get the sink id of the device that audio is being played. Initial value is
  // empty and the default device is being used.
  void GetSinkId(nsString& aSinkId) const {
    MOZ_ASSERT(NS_IsMainThread());
    aSinkId = mSink.first;
  }

  // This is used to notify MediaElementAudioSourceNode that media element is
  // allowed to play when media element is used as a source for web audio, so
  // that we can start AudioContext if it was not allowed to start.
  RefPtr<GenericNonExclusivePromise> GetAllowedToPlayPromise();

  bool GetShowPosterFlag() const { return mShowPoster; }

  bool IsAudible() const;

  // Return key system in use if we have one, otherwise return nothing.
  Maybe<nsAutoString> GetKeySystem() const override;

 protected:
  virtual ~HTMLMediaElement();

  class AudioChannelAgentCallback;
  class ChannelLoader;
  class ErrorSink;
  class MediaElementTrackSource;
  class MediaLoadListener;
  class MediaStreamRenderer;
  class MediaStreamTrackListener;
  class ShutdownObserver;
  class TitleChangeObserver;
  class MediaControlKeyListener;

  MediaDecoderOwner::NextFrameStatus NextFrameStatus();

  void SetDecoder(MediaDecoder* aDecoder);

  void PlayInternal(bool aHandlingUserInput);

  // See spec, https://html.spec.whatwg.org/#internal-pause-steps
  void PauseInternal();

  /** Use this method to change the mReadyState member, so required
   * events can be fired.
   */
  void ChangeReadyState(nsMediaReadyState aState);

  /**
   * Use this method to change the mNetworkState member, so required
   * actions will be taken during the transition.
   */
  void ChangeNetworkState(nsMediaNetworkState aState);

  /**
   * The MediaElement will be responsible for creating and releasing the audio
   * wakelock depending on the playing and audible state.
   */
  virtual void WakeLockRelease();
  virtual void UpdateWakeLock();

  void CreateAudioWakeLockIfNeeded();
  void ReleaseAudioWakeLockIfExists();
  RefPtr<WakeLock> mWakeLock;

  /**
   * Logs a warning message to the web console to report various failures.
   * aMsg is the localized message identifier, aParams is the parameters to
   * be substituted into the localized message, and aParamCount is the number
   * of parameters in aParams.
   */
  void ReportLoadError(const char* aMsg, const nsTArray<nsString>& aParams =
                                             nsTArray<nsString>());

  /**
   * Log message to web console.
   */
  void ReportToConsole(
      uint32_t aErrorFlags, const char* aMsg,
      const nsTArray<nsString>& aParams = nsTArray<nsString>()) const;

  /**
   * Changes mHasPlayedOrSeeked to aValue. If mHasPlayedOrSeeked changes
   * we'll force a reflow so that the video frame gets reflowed to reflect
   * the poster hiding or showing immediately.
   */
  void SetPlayedOrSeeked(bool aValue);

  /**
   * Initialize the media element for playback of aStream
   */
  void SetupSrcMediaStreamPlayback(DOMMediaStream* aStream);
  /**
   * Stop playback on mSrcStream.
   */
  void EndSrcMediaStreamPlayback();
  /**
   * Ensure we're playing mSrcStream if and only if we're not paused.
   */
  enum { REMOVING_SRC_STREAM = 0x1 };
  void UpdateSrcMediaStreamPlaying(uint32_t aFlags = 0);

  /**
   * Ensure currentTime progresses if and only if we're potentially playing
   * mSrcStream. Called by the watch manager while we're playing mSrcStream, and
   * one of the inputs to the potentially playing algorithm changes.
   */
  void UpdateSrcStreamPotentiallyPlaying();

  /**
   * mSrcStream's graph's CurrentTime() has been updated. It might be time to
   * fire "timeupdate".
   */
  void UpdateSrcStreamTime();

  /**
   * Called after a tail dispatch when playback of mSrcStream ended, to comply
   * with the spec where we must start reporting true for the ended attribute
   * after the event loop returns to step 1. A MediaStream could otherwise be
   * manipulated to end a HTMLMediaElement synchronously.
   */
  void UpdateSrcStreamReportPlaybackEnded();

  /**
   * Called by our DOMMediaStream::TrackListener when a new MediaStreamTrack has
   * been added to the playback stream of |mSrcStream|.
   */
  void NotifyMediaStreamTrackAdded(const RefPtr<MediaStreamTrack>& aTrack);

  /**
   * Called by our DOMMediaStream::TrackListener when a MediaStreamTrack in
   * |mSrcStream|'s playback stream has ended.
   */
  void NotifyMediaStreamTrackRemoved(const RefPtr<MediaStreamTrack>& aTrack);

  /**
   * Convenience method to get in a single list all enabled AudioTracks and, if
   * this is a video element, the selected VideoTrack.
   */
  void GetAllEnabledMediaTracks(nsTArray<RefPtr<MediaTrack>>& aTracks);

  /**
   * Enables or disables all tracks forwarded from mSrcStream to all
   * OutputMediaStreams. We do this for muting the tracks when pausing,
   * and unmuting when playing the media element again.
   */
  void SetCapturedOutputStreamsEnabled(bool aEnabled);

  /**
   * Returns true if output tracks should be muted, based on the state of this
   * media element.
   */
  enum class OutputMuteState { Muted, Unmuted };
  OutputMuteState OutputTracksMuted();

  /**
   * Sets the muted state of all output track sources. They are muted when we're
   * paused and unmuted otherwise.
   */
  void UpdateOutputTracksMuting();

  /**
   * Create a new MediaStreamTrack for the TrackSource corresponding to aTrack
   * and add it to the DOMMediaStream in aOutputStream. This automatically sets
   * the output track to enabled or disabled depending on our current playing
   * state.
   */
  enum class AddTrackMode { ASYNC, SYNC };
  void AddOutputTrackSourceToOutputStream(
      MediaElementTrackSource* aSource, OutputMediaStream& aOutputStream,
      AddTrackMode aMode = AddTrackMode::ASYNC);

  /**
   * Creates output track sources when this media element is captured, tracks
   * exist, playback is not ended and readyState is >= HAVE_METADATA.
   */
  void UpdateOutputTrackSources();

  /**
   * Returns an DOMMediaStream containing the played contents of this
   * element. When aBehavior is FINISH_WHEN_ENDED, when this element ends
   * playback we will finish the stream and not play any more into it.  When
   * aType is CONTINUE_WHEN_ENDED, ending playback does not finish the stream.
   * The stream will never finish.
   *
   * When aType is CAPTURE_AUDIO, we stop playout of audio and instead route it
   * to the DOMMediaStream. Volume and mute state will be applied to the audio
   * reaching the stream. No video tracks will be captured in this case.
   *
   * aGraph may be null if the stream's tracks do not need to use a
   * specific graph.
   */
  already_AddRefed<DOMMediaStream> CaptureStreamInternal(
      StreamCaptureBehavior aFinishBehavior,
      StreamCaptureType aStreamCaptureType, MediaTrackGraph* aGraph);

  /**
   * Initialize a decoder as a clone of an existing decoder in another
   * element.
   * mLoadingSrc must already be set.
   */
  nsresult InitializeDecoderAsClone(ChannelMediaDecoder* aOriginal);

  /**
   * Call Load() and FinishDecoderSetup() on the decoder. It also handle
   * resource cloning if DecoderType is ChannelMediaDecoder.
   */
  template <typename DecoderType, typename... LoadArgs>
  nsresult SetupDecoder(DecoderType* aDecoder, LoadArgs&&... aArgs);

  /**
   * Initialize a decoder to load the given channel. The decoder's stream
   * listener is returned via aListener.
   * mLoadingSrc must already be set.
   */
  nsresult InitializeDecoderForChannel(nsIChannel* aChannel,
                                       nsIStreamListener** aListener);

  /**
   * Finish setting up the decoder after Load() has been called on it.
   * Called by InitializeDecoderForChannel/InitializeDecoderAsClone.
   */
  nsresult FinishDecoderSetup(MediaDecoder* aDecoder);

  /**
   * Call this after setting up mLoadingSrc and mDecoder.
   */
  void AddMediaElementToURITable();
  /**
   * Call this before modifying mLoadingSrc.
   */
  void RemoveMediaElementFromURITable();
  /**
   * Call this to find a media element with the same NodePrincipal and
   * mLoadingSrc set to aURI, and with a decoder on which Load() has been
   * called.
   */
  HTMLMediaElement* LookupMediaElementURITable(nsIURI* aURI);

  /**
   * Shutdown and clear mDecoder and maintain associated invariants.
   */
  void ShutdownDecoder();
  /**
   * Execute the initial steps of the load algorithm that ensure existing
   * loads are aborted, the element is emptied, and a new load ID is
   * created.
   */
  void AbortExistingLoads();

  /**
   * This is the dedicated media source failure steps.
   * Called when all potential resources are exhausted. Changes network
   * state to NETWORK_NO_SOURCE, and sends error event with code
   * MEDIA_ERR_SRC_NOT_SUPPORTED.
   */
  void NoSupportedMediaSourceError(
      const nsACString& aErrorDetails = nsCString());

  /**
   * Per spec, Failed with elements: Queue a task, using the DOM manipulation
   * task source, to fire a simple event named error at the candidate element.
   * So dispatch |QueueLoadFromSourceTask| to main thread to make sure the task
   * will be executed later than loadstart event.
   */
  void DealWithFailedElement(nsIContent* aSourceElement);

  /**
   * Attempts to load resources from the <source> children. This is a
   * substep of the resource selection algorithm. Do not call this directly,
   * call QueueLoadFromSourceTask() instead.
   */
  void LoadFromSourceChildren();

  /**
   * Asynchronously awaits a stable state, and then causes
   * LoadFromSourceChildren() to be called on the main threads' event loop.
   */
  void QueueLoadFromSourceTask();

  /**
   * Runs the media resource selection algorithm.
   */
  void SelectResource();

  /**
   * A wrapper function that allows us to cleanly reset flags after a call
   * to SelectResource()
   */
  void SelectResourceWrapper();

  /**
   * Asynchronously awaits a stable state, and then causes SelectResource()
   * to be run on the main thread's event loop.
   */
  void QueueSelectResourceTask();

  /**
   * When loading a new source on an existing media element, make sure to reset
   * everything that is accessible using the media element API.
   */
  void ResetState();

  /**
   * The resource-fetch algorithm step of the load algorithm.
   */
  MediaResult LoadResource();

  /**
   * Selects the next <source> child from which to load a resource. Called
   * during the resource selection algorithm. Stores the return value in
   * mSourceLoadCandidate before returning.
   */
  HTMLSourceElement* GetNextSource();

  /**
   * Changes mDelayingLoadEvent, and will call BlockOnLoad()/UnblockOnLoad()
   * on the owning document, so it can delay the load event firing.
   */
  void ChangeDelayLoadStatus(bool aDelay);

  /**
   * If we suspended downloading after the first frame, unsuspend now.
   */
  void StopSuspendingAfterFirstFrame();

  /**
   * Called when our channel is redirected to another channel.
   * Updates our mChannel reference to aNewChannel.
   */
  nsresult OnChannelRedirect(nsIChannel* aChannel, nsIChannel* aNewChannel,
                             uint32_t aFlags);

  /**
   * Call this to reevaluate whether we should be holding a self-reference.
   */
  void AddRemoveSelfReference();

  /**
   * Called when "xpcom-shutdown" event is received.
   */
  void NotifyShutdownEvent();

  /**
   * Possible values of the 'preload' attribute.
   */
  enum PreloadAttrValue : uint8_t {
    PRELOAD_ATTR_EMPTY,     // set to ""
    PRELOAD_ATTR_NONE,      // set to "none"
    PRELOAD_ATTR_METADATA,  // set to "metadata"
    PRELOAD_ATTR_AUTO       // set to "auto"
  };

  /**
   * The preloading action to perform. These dictate how we react to the
   * preload attribute. See mPreloadAction.
   */
  enum PreloadAction {
    PRELOAD_UNDEFINED = 0,  // not determined - used only for initialization
    PRELOAD_NONE = 1,       // do not preload
    PRELOAD_METADATA = 2,   // preload only the metadata (and first frame)
    PRELOAD_ENOUGH = 3      // preload enough data to allow uninterrupted
                            // playback
  };

  /**
   * The guts of Load(). Load() acts as a wrapper around this which sets
   * mIsDoingExplicitLoad to true so that when script calls 'load()'
   * preload-none will be automatically upgraded to preload-metadata.
   */
  void DoLoad();

  /**
   * Suspends the load of mLoadingSrc, so that it can be resumed later
   * by ResumeLoad(). This is called when we have a media with a 'preload'
   * attribute value of 'none', during the resource selection algorithm.
   */
  void SuspendLoad();

  /**
   * Resumes a previously suspended load (suspended by SuspendLoad(uri)).
   * Will continue running the resource selection algorithm.
   * Sets mPreloadAction to aAction.
   */
  void ResumeLoad(PreloadAction aAction);

  /**
   * Handle a change to the preload attribute. Should be called whenever the
   * value (or presence) of the preload attribute changes. The change in
   * attribute value may cause a change in the mPreloadAction of this
   * element. If there is a change then this method will initiate any
   * behaviour that is necessary to implement the action.
   */
  void UpdatePreloadAction();

  /**
   * Fire progress events if needed according to the time and byte constraints
   * outlined in the specification. aHaveNewProgress is true if progress has
   * just been detected.  Otherwise the method is called as a result of the
   * progress timer.
   */
  void CheckProgress(bool aHaveNewProgress);
  static void ProgressTimerCallback(nsITimer* aTimer, void* aClosure);
  /**
   * Start timer to update download progress.
   */
  void StartProgressTimer();
  /**
   * Start sending progress and/or stalled events.
   */
  void StartProgress();
  /**
   * Stop progress information timer and events.
   */
  void StopProgress();

  /**
   * Dispatches an error event to a child source element.
   */
  void DispatchAsyncSourceError(nsIContent* aSourceElement);

  /**
   * Resets the media element for an error condition as per aErrorCode.
   * aErrorCode must be one of WebIDL HTMLMediaElement error codes.
   */
  void Error(uint16_t aErrorCode,
             const nsACString& aErrorDetails = nsCString());

  /**
   * Returns the URL spec of the currentSrc.
   **/
  void GetCurrentSpec(nsCString& aString);

  /**
   * Process any media fragment entries in the URI
   */
  void ProcessMediaFragmentURI();

  /**
   * Mute or unmute the audio and change the value that the |muted| map.
   */
  void SetMutedInternal(uint32_t aMuted);
  /**
   * Update the volume of the output audio stream to match the element's
   * current mMuted/mVolume/mAudioChannelFaded state.
   */
  void SetVolumeInternal();

  /**
   * Suspend or resume element playback and resource download.  When we suspend
   * playback, event delivery would also be suspended (and events queued) until
   * the element is resumed.
   */
  void SuspendOrResumeElement(bool aSuspendElement);

  // Get the HTMLMediaElement object if the decoder is being used from an
  // HTML media element, and null otherwise.
  HTMLMediaElement* GetMediaElement() final { return this; }

  // Return true if decoding should be paused
  bool GetPaused() final { return Paused(); }

  // Seeks to aTime seconds. aSeekType can be Exact to seek to exactly the
  // seek target, or PrevSyncPoint if a quicker but less precise seek is
  // desired, and we'll seek to the sync point (keyframe and/or start of the
  // next block of audio samples) preceeding seek target.
  void Seek(double aTime, SeekTarget::Type aSeekType, ErrorResult& aRv);

  // Update the audio channel playing state
  void UpdateAudioChannelPlayingState();

  // Adds to the element's list of pending text tracks each text track
  // in the element's list of text tracks whose text track mode is not disabled
  // and whose text track readiness state is loading.
  void PopulatePendingTextTrackList();

  // Gets a reference to the MediaElement's TextTrackManager. If the
  // MediaElement doesn't yet have one then it will create it.
  TextTrackManager* GetOrCreateTextTrackManager();

  // Recomputes ready state and fires events as necessary based on current
  // state.
  void UpdateReadyStateInternal();

  // Create or destroy the captured stream.
  void AudioCaptureTrackChange(bool aCapture);

  // If the network state is empty and then we would trigger DoLoad().
  void MaybeDoLoad();

  // Anything we need to check after played success and not related with spec.
  void UpdateCustomPolicyAfterPlayed();

  // Returns a StreamCaptureType populated with the right bits, depending on the
  // tracks this HTMLMediaElement has.
  StreamCaptureType CaptureTypeForElement();

  // True if this element can be captured, false otherwise.
  bool CanBeCaptured(StreamCaptureType aCaptureType);

  using nsGenericHTMLElement::DispatchEvent;
  // For nsAsyncEventRunner.
  nsresult DispatchEvent(const nsAString& aName);

  already_AddRefed<nsMediaEventRunner> GetEventRunner(
      const nsAString& aName, EventFlag aFlag = EventFlag::eNone);

  // This method moves the mPendingPlayPromises into a temperate object. So the
  // mPendingPlayPromises is cleared after this method call.
  nsTArray<RefPtr<PlayPromise>> TakePendingPlayPromises();

  // This method snapshots the mPendingPlayPromises by TakePendingPlayPromises()
  // and queues a task to resolve them.
  void AsyncResolvePendingPlayPromises();

  // This method snapshots the mPendingPlayPromises by TakePendingPlayPromises()
  // and queues a task to reject them.
  void AsyncRejectPendingPlayPromises(nsresult aError);

  // This method snapshots the mPendingPlayPromises by TakePendingPlayPromises()
  // and queues a task to resolve them also to dispatch a "playing" event.
  void NotifyAboutPlaying();

  already_AddRefed<Promise> CreateDOMPromise(ErrorResult& aRv) const;

  // Pass information for deciding the video decode mode to decoder.
  void NotifyDecoderActivityChanges() const;

  // Constructs an AudioTrack in mAudioTrackList if aInfo reports that audio is
  // available, and a VideoTrack in mVideoTrackList if aInfo reports that video
  // is available.
  void ConstructMediaTracks(const MediaInfo* aInfo);

  // Removes all MediaTracks from mAudioTrackList and mVideoTrackList and fires
  // "removetrack" on the lists accordingly.
  // Note that by spec, this should not fire "removetrack". However, it appears
  // other user agents do, per
  // https://wpt.fyi/results/media-source/mediasource-avtracks.html.
  void RemoveMediaTracks();

  // Mark the decoder owned by the element as tainted so that the
  // suspend-video-decoder is disabled.
  void MarkAsTainted();

  virtual void AfterSetAttr(int32_t aNameSpaceID, nsAtom* aName,
                            const nsAttrValue* aValue,
                            const nsAttrValue* aOldValue,
                            nsIPrincipal* aMaybeScriptedPrincipal,
                            bool aNotify) override;
  virtual void OnAttrSetButNotChanged(int32_t aNamespaceID, nsAtom* aName,
                                      const nsAttrValueOrString& aValue,
                                      bool aNotify) override;

  bool DetachExistingMediaKeys();
  bool TryRemoveMediaKeysAssociation();
  void RemoveMediaKeys();
  bool AttachNewMediaKeys();
  bool TryMakeAssociationWithCDM(CDMProxy* aProxy);
  void MakeAssociationWithCDMResolved();
  void SetCDMProxyFailure(const MediaResult& aResult);
  void ResetSetMediaKeysTempVariables();

  void PauseIfShouldNotBePlaying();

  WatchManager<HTMLMediaElement> mWatchManager;

  // When the play is not allowed, dispatch related events which are used for
  // testing or changing control UI.
  void DispatchEventsWhenPlayWasNotAllowed();

  // When the doc is blocked permanantly, we would dispatch event to notify
  // front-end side to show blocking icon.
  void MaybeNotifyAutoplayBlocked();

  // Dispatch event for video control when video gets blocked in order to show
  // the click-to-play icon.
  void DispatchBlockEventForVideoControl();

  // When playing state change, we have to notify MediaControl in the chrome
  // process in order to keep its playing state correct.
  void NotifyMediaControlPlaybackStateChanged();

  // Clear the timer when we want to continue listening to the media control
  // key events.
  void ClearStopMediaControlTimerIfNeeded();

  // Sets a secondary renderer for mSrcStream, so this media element can be
  // rendered in Picture-in-Picture mode when playing a MediaStream. A null
  // aContainer will unset the secondary renderer. aFirstFrameOutput allows
  // for injecting a listener of the callers choice for rendering the first
  // frame.
  void SetSecondaryMediaStreamRenderer(
      VideoFrameContainer* aContainer,
      FirstFrameVideoOutput* aFirstFrameOutput = nullptr);

  // This function is used to update the status of media control when the media
  // changes its status of being used in the Picture-in-Picture mode.
  void UpdateMediaControlAfterPictureInPictureModeChanged();

  // The current decoder. Load() has been called on this decoder.
  // At most one of mDecoder and mSrcStream can be non-null.
  RefPtr<MediaDecoder> mDecoder;

  // A reference to the VideoFrameContainer which contains the current frame
  // of video to display.
  RefPtr<VideoFrameContainer> mVideoFrameContainer;

  // Holds a reference to the MediaStream that has been set in the src
  // attribute.
  RefPtr<DOMMediaStream> mSrcAttrStream;

  // Holds the triggering principal for the src attribute.
  nsCOMPtr<nsIPrincipal> mSrcAttrTriggeringPrincipal;

  // Holds a reference to the MediaStream that we're actually playing.
  // At most one of mDecoder and mSrcStream can be non-null.
  RefPtr<DOMMediaStream> mSrcStream;

  // The MediaStreamRenderer handles rendering of our selected video track, and
  // enabled audio tracks, while mSrcStream is set.
  RefPtr<MediaStreamRenderer> mMediaStreamRenderer;

  // The secondary MediaStreamRenderer handles rendering of our selected video
  // track to a secondary VideoFrameContainer, while mSrcStream is set.
  RefPtr<MediaStreamRenderer> mSecondaryMediaStreamRenderer;

  // True once PlaybackEnded() is called and we're playing a MediaStream.
  // Reset to false if we start playing mSrcStream again.
  Watchable<bool> mSrcStreamPlaybackEnded = {
      false, "HTMLMediaElement::mSrcStreamPlaybackEnded"};

  // Mirrors mSrcStreamPlaybackEnded after a tail dispatch when set to true,
  // but may be be forced to false directly. To accomodate when an application
  // ends playback synchronously by manipulating mSrcStream or its tracks,
  // e.g., through MediaStream.removeTrack(), or MediaStreamTrack.stop().
  bool mSrcStreamReportPlaybackEnded = false;

  // Holds a reference to the stream connecting this stream to the window
  // capture sink.
  UniquePtr<MediaStreamWindowCapturer> mStreamWindowCapturer;

  // Holds references to the DOM wrappers for the MediaStreams that we're
  // writing to.
  nsTArray<OutputMediaStream> mOutputStreams;

  // Mapping for output tracks, from dom::MediaTrack ids to the
  // MediaElementTrackSource that represents the source of all corresponding
  // MediaStreamTracks captured from this element.
  nsRefPtrHashtable<nsStringHashKey, MediaElementTrackSource>
      mOutputTrackSources;

  // The currently selected video stream track.
  RefPtr<VideoStreamTrack> mSelectedVideoStreamTrack;

  const RefPtr<ShutdownObserver> mShutdownObserver;

  const RefPtr<TitleChangeObserver> mTitleChangeObserver;

  // Holds a reference to the MediaSource, if any, referenced by the src
  // attribute on the media element.
  RefPtr<MediaSource> mSrcMediaSource;

  // Holds a reference to the MediaSource supplying data for playback.  This
  // may either match mSrcMediaSource or come from Source element children.
  // This is set when and only when mLoadingSrc corresponds to an object url
  // that resolved to a MediaSource.
  RefPtr<MediaSource> mMediaSource;

  RefPtr<ChannelLoader> mChannelLoader;

  // Points to the child source elements, used to iterate through the children
  // when selecting a resource to load.  This is the previous sibling of the
  // child considered the current 'candidate' in:
  // https://html.spec.whatwg.org/multipage/media.html#concept-media-load-algorithm
  //
  // mSourcePointer == nullptr, we will next try to load |GetFirstChild()|.
  // mSourcePointer == GetLastChild(), we've exhausted all sources, waiting
  // for new elements to be appended.
  nsCOMPtr<nsIContent> mSourcePointer;

  // Points to the document whose load we're blocking. This is the document
  // we're bound to when loading starts.
  nsCOMPtr<Document> mLoadBlockedDoc;

  // This is used to help us block/resume the event delivery.
  class EventBlocker;
  RefPtr<EventBlocker> mEventBlocker;

  // Media loading flags. See:
  //   http://www.whatwg.org/specs/web-apps/current-work/#video)
  nsMediaNetworkState mNetworkState = HTMLMediaElement_Binding::NETWORK_EMPTY;
  Watchable<nsMediaReadyState> mReadyState = {
      HTMLMediaElement_Binding::HAVE_NOTHING, "HTMLMediaElement::mReadyState"};

  enum LoadAlgorithmState {
    // No load algorithm instance is waiting for a source to be added to the
    // media in order to continue loading.
    NOT_WAITING,
    // We've run the load algorithm, and we tried all source children of the
    // media element, and failed to load any successfully. We're waiting for
    // another source element to be added to the media element, and will try
    // to load any such element when its added.
    WAITING_FOR_SOURCE
  };

  // The current media load ID. This is incremented every time we start a
  // new load. Async events note the ID when they're first sent, and only fire
  // if the ID is unchanged when they come to fire.
  uint32_t mCurrentLoadID = 0;

  // Denotes the waiting state of a load algorithm instance. When the load
  // algorithm is waiting for a source element child to be added, this is set
  // to WAITING_FOR_SOURCE, otherwise it's NOT_WAITING.
  LoadAlgorithmState mLoadWaitStatus = NOT_WAITING;

  // Current audio volume
  double mVolume = 1.0;

  // True if the audio track is not silent.
  bool mIsAudioTrackAudible = false;

  enum MutedReasons {
    MUTED_BY_CONTENT = 0x01,
    MUTED_BY_INVALID_PLAYBACK_RATE = 0x02,
    MUTED_BY_AUDIO_CHANNEL = 0x04,
    MUTED_BY_AUDIO_TRACK = 0x08
  };

  uint32_t mMuted = 0;

  UniquePtr<const MetadataTags> mTags;

  // URI of the resource we're attempting to load. This stores the value we
  // return in the currentSrc attribute. Use GetCurrentSrc() to access the
  // currentSrc attribute.
  // This is always the original URL we're trying to load --- before
  // redirects etc.
  nsCOMPtr<nsIURI> mLoadingSrc;

  // The triggering principal for the current source.
  nsCOMPtr<nsIPrincipal> mLoadingSrcTriggeringPrincipal;

  // Stores the current preload action for this element. Initially set to
  // PRELOAD_UNDEFINED, its value is changed by calling
  // UpdatePreloadAction().
  PreloadAction mPreloadAction = PRELOAD_UNDEFINED;

  // Time that the last timeupdate event was queued. Read/Write from the
  // main thread only.
  TimeStamp mQueueTimeUpdateRunnerTime;

  // Time that the last timeupdate event was fired. Read/Write from the
  // main thread only.
  TimeStamp mLastTimeUpdateDispatchTime;

  // Time that the last progress event was fired. Read/Write from the
  // main thread only.
  TimeStamp mProgressTime;

  // Time that data was last read from the media resource. Used for
  // computing if the download has stalled and to rate limit progress events
  // when data is arriving slower than PROGRESS_MS.
  // Read/Write from the main thread only.
  TimeStamp mDataTime;

  // Media 'currentTime' value when the last timeupdate event was queued.
  // Read/Write from the main thread only.
  double mLastCurrentTime = 0.0;

  // Logical start time of the media resource in seconds as obtained
  // from any media fragments. A negative value indicates that no
  // fragment time has been set. Read/Write from the main thread only.
  double mFragmentStart = -1.0;

  // Logical end time of the media resource in seconds as obtained
  // from any media fragments. A negative value indicates that no
  // fragment time has been set. Read/Write from the main thread only.
  double mFragmentEnd = -1.0;

  // The defaultPlaybackRate attribute gives the desired speed at which the
  // media resource is to play, as a multiple of its intrinsic speed.
  double mDefaultPlaybackRate = 1.0;

  // The playbackRate attribute gives the speed at which the media resource
  // plays, as a multiple of its intrinsic speed. If it is not equal to the
  // defaultPlaybackRate, then the implication is that the user is using a
  // feature such as fast forward or slow motion playback.
  double mPlaybackRate = 1.0;

  // True if pitch correction is applied when playbackRate is set to a
  // non-intrinsic value.
  bool mPreservesPitch = true;

  // Reference to the source element last returned by GetNextSource().
  // This is the child source element which we're trying to load from.
  nsCOMPtr<nsIContent> mSourceLoadCandidate;

  // Range of time played.
  RefPtr<TimeRanges> mPlayed;

  // Timer used for updating progress events.
  nsCOMPtr<nsITimer> mProgressTimer;

  // Encrypted Media Extension media keys.
  RefPtr<MediaKeys> mMediaKeys;
  RefPtr<MediaKeys> mIncomingMediaKeys;
  // The dom promise is used for HTMLMediaElement::SetMediaKeys.
  RefPtr<DetailedPromise> mSetMediaKeysDOMPromise;
  // Used to indicate if the MediaKeys attaching operation is on-going or not.
  bool mAttachingMediaKey = false;
  MozPromiseRequestHolder<SetCDMPromise> mSetCDMRequest;

  // Stores the time at the start of the current 'played' range.
  double mCurrentPlayRangeStart = 1.0;

  // True if loadeddata has been fired.
  bool mLoadedDataFired = false;

  // One of the factors determines whether a media element with 'autoplay'
  // attribute is allowed to start playing.
  // https://html.spec.whatwg.org/multipage/media.html#can-autoplay-flag
  bool mCanAutoplayFlag = true;

  // Playback of the video is paused either due to calling the
  // 'Pause' method, or playback not yet having started.
  Watchable<bool> mPaused = {true, "HTMLMediaElement::mPaused"};

  // The following two fields are here for the private storage of the builtin
  // video controls, and control 'casting' of the video to external devices
  // (TVs, projectors etc.)
  // True if casting is currently allowed
  bool mAllowCasting = false;
  // True if currently casting this video
  bool mIsCasting = false;

  // Set while there are some OutputMediaStreams this media element's enabled
  // and selected tracks are captured into. When set, all tracks are captured
  // into the graph of this dummy track.
  // NB: This is a SharedDummyTrack to allow non-default graphs (AudioContexts
  // with an explicit sampleRate defined) to capture this element. When
  // cross-graph tracks are supported, this can become a bool.
  Watchable<RefPtr<SharedDummyTrack>> mTracksCaptured;

  // True if the sound is being captured.
  bool mAudioCaptured = false;

  // If TRUE then the media element was actively playing before the currently
  // in progress seeking. If FALSE then the media element is either not seeking
  // or was not actively playing before the current seek. Used to decide whether
  // to raise the 'waiting' event as per 4.7.1.8 in HTML 5 specification.
  bool mPlayingBeforeSeek = false;

  // True if this element is suspended because the document is inactive or the
  // inactive docshell is not allowing media to play.
  bool mSuspendedByInactiveDocOrDocshell = false;

  // True if we're running the "load()" method.
  bool mIsRunningLoadMethod = false;

  // True if we're running or waiting to run queued tasks due to an explicit
  // call to "load()".
  bool mIsDoingExplicitLoad = false;

  // True if we're loading the resource from the child source elements.
  bool mIsLoadingFromSourceChildren = false;

  // True if we're delaying the "load" event. They are delayed until either
  // an error occurs, or the first frame is loaded.
  bool mDelayingLoadEvent = false;

  // True when we've got a task queued to call SelectResource(),
  // or while we're running SelectResource().
  bool mIsRunningSelectResource = false;

  // True when we already have select resource call queued
  bool mHaveQueuedSelectResource = false;

  // True if we suspended the decoder because we were paused,
  // preloading metadata is enabled, autoplay was not enabled, and we loaded
  // the first frame.
  bool mSuspendedAfterFirstFrame = false;

  // True if we are allowed to suspend the decoder because we were paused,
  // preloading metdata was enabled, autoplay was not enabled, and we loaded
  // the first frame.
  bool mAllowSuspendAfterFirstFrame = true;

  // True if we've played or completed a seek. We use this to determine
  // when the poster frame should be shown.
  bool mHasPlayedOrSeeked = false;

  // True if we've added a reference to ourselves to keep the element
  // alive while no-one is referencing it but the element may still fire
  // events of its own accord.
  bool mHasSelfReference = false;

  // True if we've received a notification that the engine is shutting
  // down.
  bool mShuttingDown = false;

  // True if we've suspended a load in the resource selection algorithm
  // due to loading a preload:none media. When true, the resource we'll
  // load when the user initiates either playback or an explicit load is
  // stored in mPreloadURI.
  bool mSuspendedForPreloadNone = false;

  // True if we've connected mSrcStream to the media element output.
  bool mSrcStreamIsPlaying = false;

  // True if we should set nsIClassOfService::UrgentStart to the channel to
  // get the response ASAP for better user responsiveness.
  bool mUseUrgentStartForChannel = false;

  // The CORS mode when loading the media element
  CORSMode mCORSMode = CORS_NONE;

  // Info about the played media.
  MediaInfo mMediaInfo;

  // True if the media has encryption information.
  bool mIsEncrypted = false;

  enum WaitingForKeyState {
    NOT_WAITING_FOR_KEY = 0,
    WAITING_FOR_KEY = 1,
    WAITING_FOR_KEY_DISPATCHED = 2
  };

  // True when the CDM cannot decrypt the current block due to lacking a key.
  // Note: the "waitingforkey" event is not dispatched until all decoded data
  // has been rendered.
  WaitingForKeyState mWaitingForKey = NOT_WAITING_FOR_KEY;

  // Listens for waitingForKey events from the owned decoder.
  MediaEventListener mWaitingForKeyListener;

  // Init Data that needs to be sent in 'encrypted' events in MetadataLoaded().
  EncryptionInfo mPendingEncryptedInitData;

  // True if the media's channel's download has been suspended.
  Watchable<bool> mDownloadSuspendedByCache = {
      false, "HTMLMediaElement::mDownloadSuspendedByCache"};

  // Disable the video playback by track selection. This flag might not be
  // enough if we ever expand the ability of supporting multi-tracks video
  // playback.
  bool mDisableVideo = false;

  RefPtr<TextTrackManager> mTextTrackManager;

  RefPtr<AudioTrackList> mAudioTrackList;

  RefPtr<VideoTrackList> mVideoTrackList;

  UniquePtr<MediaStreamTrackListener> mMediaStreamTrackListener;

  // The principal guarding mVideoFrameContainer access when playing a
  // MediaStream.
  nsCOMPtr<nsIPrincipal> mSrcStreamVideoPrincipal;

  // True if the autoplay media was blocked because it hadn't loaded metadata
  // yet.
  bool mBlockedAsWithoutMetadata = false;

  // This promise is used to notify MediaElementAudioSourceNode that media
  // element is allowed to play when MediaElement is used as a source for web
  // audio.
  MozPromiseHolder<GenericNonExclusivePromise> mAllowedToPlayPromise;

  // True if media has ever been blocked for autoplay, it's used to notify front
  // end to show the correct blocking icon when the document goes back from
  // bfcache.
  bool mHasEverBeenBlockedForAutoplay = false;

  // True if we have dispatched a task for text track changed, will be unset
  // when we starts processing text track changed.
  // https://html.spec.whatwg.org/multipage/media.html#pending-text-track-change-notification-flag
  bool mPendingTextTrackChanged = false;

 public:
  // This function will be called whenever a text track that is in a media
  // element's list of text tracks has its text track mode change value
  void NotifyTextTrackModeChanged();

 private:
  friend class nsMediaEventRunner;
  friend class nsResolveOrRejectPendingPlayPromisesRunner;

  already_AddRefed<PlayPromise> CreatePlayPromise(ErrorResult& aRv) const;

  virtual void MaybeBeginCloningVisually(){};

  uint32_t GetPreloadDefault() const;
  uint32_t GetPreloadDefaultAuto() const;

  /**
   * This function is called by AfterSetAttr and OnAttrSetButNotChanged.
   * It will not be called if the value is being unset.
   *
   * @param aNamespaceID the namespace of the attr being set
   * @param aName the localname of the attribute being set
   * @param aNotify Whether we plan to notify document observers.
   */
  void AfterMaybeChangeAttr(int32_t aNamespaceID, nsAtom* aName, bool aNotify);

  // True if Init() has been called after construction
  bool mInitialized = false;

  // True if user has called load(), seek() or element has started playing
  // before. It's *only* use for `click-to-play` blocking autoplay policy.
  // In addition, we would reset this once media aborts current load.
  bool mIsBlessed = false;

  // True if the first frame has been successfully loaded.
  Watchable<bool> mFirstFrameLoaded = {false,
                                       "HTMLMediaElement::mFirstFrameLoaded"};

  // Media elements also have a default playback start position, which must
  // initially be set to zero seconds. This time is used to allow the element to
  // be seeked even before the media is loaded.
  double mDefaultPlaybackStartPosition = 0.0;

  // True if media element has been marked as 'tainted' and can't
  // participate in video decoder suspending.
  bool mHasSuspendTaint = false;

  // True if media element has been forced into being considered 'hidden'.
  // For use by mochitests. Enabling pref "media.test.video-suspend"
  bool mForcedHidden = false;

  Visibility mVisibilityState = Visibility::Untracked;

  UniquePtr<ErrorSink> mErrorSink;

  // This wrapper will handle all audio channel related stuffs, eg. the
  // operations of tab audio indicator, Fennec's media control. Note:
  // mAudioChannelWrapper might be null after GC happened.
  RefPtr<AudioChannelAgentCallback> mAudioChannelWrapper;

  // A list of pending play promises. The elements are pushed during the play()
  // method call and are resolved/rejected during further playback steps.
  nsTArray<RefPtr<PlayPromise>> mPendingPlayPromises;

  // A list of already-dispatched but not yet run
  // nsResolveOrRejectPendingPlayPromisesRunners.
  // Runners whose Run() method is called remove themselves from this list.
  // We keep track of these because the load algorithm resolves/rejects all
  // already-dispatched pending play promises.
  nsTArray<nsResolveOrRejectPendingPlayPromisesRunner*>
      mPendingPlayPromisesRunners;

  // A pending seek promise which is created at Seek() method call and is
  // resolved/rejected at AsyncResolveSeekDOMPromiseIfExists()/
  // AsyncRejectSeekDOMPromiseIfExists() methods.
  RefPtr<dom::Promise> mSeekDOMPromise;

  // Return true if the docshell is inactive and explicitly wants to stop media
  // playing in that shell.
  bool ShouldBeSuspendedByInactiveDocShell() const;

  // For debugging bug 1407148.
  void AssertReadyStateIsNothing();

  // Contains the unique id of the sink device and the device info.
  // The initial value is ("", nullptr) and the default output device is used.
  // It can contain an invalid id and info if the device has been
  // unplugged. It can be set to ("", nullptr). It follows the spec attribute:
  // https://w3c.github.io/mediacapture-output/#htmlmediaelement-extensions
  // Read/Write from the main thread only.
  std::pair<nsString, RefPtr<AudioDeviceInfo>> mSink;

  // This flag is used to control when the user agent is to show a poster frame
  // for a video element instead of showing the video contents.
  // https://html.spec.whatwg.org/multipage/media.html#show-poster-flag
  bool mShowPoster;

  // We may delay starting playback of a media for an unvisited tab until it's
  // going to foreground. We would create ResumeDelayedMediaPlaybackAgent to
  // handle related operations at the time whenever delaying media playback is
  // needed.
  void CreateResumeDelayedMediaPlaybackAgentIfNeeded();
  void ClearResumeDelayedMediaPlaybackAgentIfNeeded();
  RefPtr<ResumeDelayedPlaybackAgent> mResumeDelayedPlaybackAgent;
  MozPromiseRequestHolder<ResumeDelayedPlaybackAgent::ResumePromise>
      mResumePlaybackRequest;

  // Return true if we have already a decoder or a src stream and don't have any
  // error.
  bool IsPlayable() const;

  // Return true if the media qualifies for being controlled by media control
  // keys.
  bool ShouldStartMediaControlKeyListener() const;

  // Start the listener if media fits the requirement of being able to be
  // controlled be media control keys.
  void StartMediaControlKeyListenerIfNeeded();

  // It's used to listen media control key, by which we would play or pause
  // media element.
  RefPtr<MediaControlKeyListener> mMediaControlKeyListener;

  // Method to update audio stream name
  void UpdateStreamName();

  // Return true if the media element is being used in picture in picture mode.
  bool IsBeingUsedInPictureInPictureMode() const;

  // Return true if we should queue a 'timeupdate' event runner to main thread.
  bool ShouldQueueTimeupdateAsyncTask(TimeupdateType aType) const;

#ifdef MOZ_WMF_CDM
  // It's used to record telemetry probe for WMFCDM playback.
  bool mIsUsingWMFCDM = false;
#endif
};

// Check if the context is chrome or has the debugger or tabs permission
bool HasDebuggerOrTabsPrivilege(JSContext* aCx, JSObject* aObj);

}  // namespace mozilla::dom

#endif  // mozilla_dom_HTMLMediaElement_h