summaryrefslogtreecommitdiffstats
path: root/dom/base/nsDocument.h
blob: 4ab28584085a6e23ec5b3adf684574bb879f67d3 (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
/* -*- 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/. */

/*
 * Base class for all our document implementations.
 */

#ifndef nsDocument_h___
#define nsDocument_h___

#include "nsIDocument.h"

#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "nsCRT.h"
#include "nsWeakReference.h"
#include "nsWeakPtr.h"
#include "nsTArray.h"
#include "nsIDOMDocument.h"
#include "nsIDOMDocumentXBL.h"
#include "nsStubDocumentObserver.h"
#include "nsIScriptGlobalObject.h"
#include "nsIContent.h"
#include "nsIPrincipal.h"
#include "nsIParser.h"
#include "nsBindingManager.h"
#include "nsInterfaceHashtable.h"
#include "nsJSThingHashtable.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIURI.h"
#include "nsScriptLoader.h"
#include "nsIRadioGroupContainer.h"
#include "nsILayoutHistoryState.h"
#include "nsIRequest.h"
#include "nsILoadGroup.h"
#include "nsTObserverArray.h"
#include "nsStubMutationObserver.h"
#include "nsIChannel.h"
#include "nsCycleCollectionParticipant.h"
#include "nsContentList.h"
#include "nsGkAtoms.h"
#include "nsIApplicationCache.h"
#include "nsIApplicationCacheContainer.h"
#include "mozilla/StyleSetHandle.h"
#include "PLDHashTable.h"
#include "nsAttrAndChildArray.h"
#include "nsDOMAttributeMap.h"
#include "nsIContentViewer.h"
#include "nsIInterfaceRequestor.h"
#include "nsILoadContext.h"
#include "nsIProgressEventSink.h"
#include "nsISecurityEventSink.h"
#include "nsIChannelEventSink.h"
#include "imgIRequest.h"
#include "mozilla/EventListenerManager.h"
#include "mozilla/EventStates.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/PendingAnimationTracker.h"
#include "mozilla/dom/DOMImplementation.h"
#include "mozilla/dom/StyleSheetList.h"
#include "nsDataHashtable.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Attributes.h"
#include "nsIDOMXPathEvaluator.h"
#include "jsfriendapi.h"
#include "ImportManager.h"
#include "mozilla/LinkedList.h"
#include "CustomElementRegistry.h"
#include "mozilla/dom/Performance.h"

#define XML_DECLARATION_BITS_DECLARATION_EXISTS   (1 << 0)
#define XML_DECLARATION_BITS_ENCODING_EXISTS      (1 << 1)
#define XML_DECLARATION_BITS_STANDALONE_EXISTS    (1 << 2)
#define XML_DECLARATION_BITS_STANDALONE_YES       (1 << 3)


class nsDOMStyleSheetSetList;
class nsDocument;
class nsIRadioVisitor;
class nsIFormControl;
struct nsRadioGroupStruct;
class nsOnloadBlocker;
class nsUnblockOnloadEvent;
class nsDOMNavigationTiming;
class nsWindowSizes;
class nsHtml5TreeOpExecutor;
class nsDocumentOnStack;
class nsISecurityConsoleMessage;
class nsPIBoxObject;

namespace mozilla {
class EventChainPreVisitor;
namespace dom {
class BoxObject;
class ImageTracker;
struct LifecycleCallbacks;
class CallbackFunction;
class DOMIntersectionObserver;
class Performance;

struct FullscreenRequest : public LinkedListElement<FullscreenRequest>
{
  explicit FullscreenRequest(Element* aElement);
  FullscreenRequest(const FullscreenRequest&) = delete;
  ~FullscreenRequest();

  Element* GetElement() const { return mElement; }
  nsDocument* GetDocument() const { return mDocument; }

private:
  RefPtr<Element> mElement;
  RefPtr<nsDocument> mDocument;

public:
  // This value should be true if the fullscreen request is
  // originated from chrome code.
  bool mIsCallerChrome = false;
  // This value denotes whether we should trigger a NewOrigin event if
  // requesting fullscreen in its document causes the origin which is
  // fullscreen to change. We may want *not* to trigger that event if
  // we're calling RequestFullScreen() as part of a continuation of a
  // request in a subdocument in different process, whereupon the caller
  // need to send some notification itself with the real origin.
  bool mShouldNotifyNewOrigin = true;
};

} // namespace dom
} // namespace mozilla

/**
 * Right now our identifier map entries contain information for 'name'
 * and 'id' mappings of a given string. This is so that
 * nsHTMLDocument::ResolveName only has to do one hash lookup instead
 * of two. It's not clear whether this still matters for performance.
 *
 * We also store the document.all result list here. This is mainly so that
 * when all elements with the given ID are removed and we remove
 * the ID's nsIdentifierMapEntry, the document.all result is released too.
 * Perhaps the document.all results should have their own hashtable
 * in nsHTMLDocument.
 */
class nsIdentifierMapEntry : public nsStringHashKey
{
public:
  typedef mozilla::dom::Element Element;
  typedef mozilla::net::ReferrerPolicy ReferrerPolicy;

  explicit nsIdentifierMapEntry(const nsAString& aKey) :
    nsStringHashKey(&aKey), mNameContentList(nullptr)
  {
  }
  explicit nsIdentifierMapEntry(const nsAString* aKey) :
    nsStringHashKey(aKey), mNameContentList(nullptr)
  {
  }
  nsIdentifierMapEntry(const nsIdentifierMapEntry& aOther) :
    nsStringHashKey(&aOther.GetKey())
  {
    NS_ERROR("Should never be called");
  }
  ~nsIdentifierMapEntry();

  void AddNameElement(nsINode* aDocument, Element* aElement);
  void RemoveNameElement(Element* aElement);
  bool IsEmpty();
  nsBaseContentList* GetNameContentList() {
    return mNameContentList;
  }
  bool HasNameElement() const {
    return mNameContentList && mNameContentList->Length() != 0;
  }

  /**
   * Returns the element if we know the element associated with this
   * id. Otherwise returns null.
   */
  Element* GetIdElement();
  /**
   * Returns the list of all elements associated with this id.
   */
  const nsTArray<Element*>& GetIdElements() const {
    return mIdContentList;
  }
  /**
   * If this entry has a non-null image element set (using SetImageElement),
   * the image element will be returned, otherwise the same as GetIdElement().
   */
  Element* GetImageIdElement();
  /**
   * Append all the elements with this id to aElements
   */
  void AppendAllIdContent(nsCOMArray<nsIContent>* aElements);
  /**
   * This can fire ID change callbacks.
   * @return true if the content could be added, false if we failed due
   * to OOM.
   */
  bool AddIdElement(Element* aElement);
  /**
   * This can fire ID change callbacks.
   */
  void RemoveIdElement(Element* aElement);
  /**
   * Set the image element override for this ID. This will be returned by
   * GetIdElement(true) if non-null.
   */
  void SetImageElement(Element* aElement);
  bool HasIdElementExposedAsHTMLDocumentProperty();

  bool HasContentChangeCallback() { return mChangeCallbacks != nullptr; }
  void AddContentChangeCallback(nsIDocument::IDTargetObserver aCallback,
                                void* aData, bool aForImage);
  void RemoveContentChangeCallback(nsIDocument::IDTargetObserver aCallback,
                                void* aData, bool aForImage);

  /**
   * Remove all elements and notify change listeners.
   */
  void ClearAndNotify();

  void Traverse(nsCycleCollectionTraversalCallback* aCallback);

  struct ChangeCallback {
    nsIDocument::IDTargetObserver mCallback;
    void* mData;
    bool mForImage;
  };

  struct ChangeCallbackEntry : public PLDHashEntryHdr {
    typedef const ChangeCallback KeyType;
    typedef const ChangeCallback* KeyTypePointer;

    explicit ChangeCallbackEntry(const ChangeCallback* aKey) :
      mKey(*aKey) { }
    ChangeCallbackEntry(const ChangeCallbackEntry& toCopy) :
      mKey(toCopy.mKey) { }

    KeyType GetKey() const { return mKey; }
    bool KeyEquals(KeyTypePointer aKey) const {
      return aKey->mCallback == mKey.mCallback &&
             aKey->mData == mKey.mData &&
             aKey->mForImage == mKey.mForImage;
    }

    static KeyTypePointer KeyToPointer(KeyType& aKey) { return &aKey; }
    static PLDHashNumber HashKey(KeyTypePointer aKey)
    {
      return mozilla::HashGeneric(aKey->mCallback, aKey->mData);
    }
    enum { ALLOW_MEMMOVE = true };

    ChangeCallback mKey;
  };

  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;

private:
  void FireChangeCallbacks(Element* aOldElement, Element* aNewElement,
                           bool aImageOnly = false);

  // empty if there are no elements with this ID.
  // The elements are stored as weak pointers.
  nsTArray<Element*> mIdContentList;
  RefPtr<nsBaseContentList> mNameContentList;
  nsAutoPtr<nsTHashtable<ChangeCallbackEntry> > mChangeCallbacks;
  RefPtr<Element> mImageElement;
};

namespace mozilla {
namespace dom {

} // namespace dom
} // namespace mozilla

class nsDocHeaderData
{
public:
  nsDocHeaderData(nsIAtom* aField, const nsAString& aData)
    : mField(aField), mData(aData), mNext(nullptr)
  {
  }

  ~nsDocHeaderData(void)
  {
    delete mNext;
  }

  nsCOMPtr<nsIAtom> mField;
  nsString          mData;
  nsDocHeaderData*  mNext;
};

class nsOnloadBlocker final : public nsIRequest
{
public:
  nsOnloadBlocker() {}

  NS_DECL_ISUPPORTS
  NS_DECL_NSIREQUEST

private:
  ~nsOnloadBlocker() {}
};

class nsExternalResourceMap
{
public:
  typedef nsIDocument::ExternalResourceLoad ExternalResourceLoad;
  nsExternalResourceMap();

  /**
   * Request an external resource document.  This does exactly what
   * nsIDocument::RequestExternalResource is documented to do.
   */
  nsIDocument* RequestResource(nsIURI* aURI,
                               nsINode* aRequestingNode,
                               nsDocument* aDisplayDocument,
                               ExternalResourceLoad** aPendingLoad);

  /**
   * Enumerate the resource documents.  See
   * nsIDocument::EnumerateExternalResources.
   */
  void EnumerateResources(nsIDocument::nsSubDocEnumFunc aCallback, void* aData);

  /**
   * Traverse ourselves for cycle-collection
   */
  void Traverse(nsCycleCollectionTraversalCallback* aCallback) const;

  /**
   * Shut ourselves down (used for cycle-collection unlink), as well
   * as for document destruction.
   */
  void Shutdown()
  {
    mPendingLoads.Clear();
    mMap.Clear();
    mHaveShutDown = true;
  }

  bool HaveShutDown() const
  {
    return mHaveShutDown;
  }

  // Needs to be public so we can traverse them sanely
  struct ExternalResource
  {
    ~ExternalResource();
    nsCOMPtr<nsIDocument> mDocument;
    nsCOMPtr<nsIContentViewer> mViewer;
    nsCOMPtr<nsILoadGroup> mLoadGroup;
  };

  // Hide all our viewers
  void HideViewers();

  // Show all our viewers
  void ShowViewers();

protected:
  class PendingLoad : public ExternalResourceLoad,
                      public nsIStreamListener
  {
    ~PendingLoad() {}

  public:
    explicit PendingLoad(nsDocument* aDisplayDocument) :
      mDisplayDocument(aDisplayDocument)
    {}

    NS_DECL_ISUPPORTS
    NS_DECL_NSISTREAMLISTENER
    NS_DECL_NSIREQUESTOBSERVER

    /**
     * Start aURI loading.  This will perform the necessary security checks and
     * so forth.
     */
    nsresult StartLoad(nsIURI* aURI, nsINode* aRequestingNode);

    /**
     * Set up an nsIContentViewer based on aRequest.  This is guaranteed to
     * put null in *aViewer and *aLoadGroup on all failures.
     */
    nsresult SetupViewer(nsIRequest* aRequest, nsIContentViewer** aViewer,
                         nsILoadGroup** aLoadGroup);

  private:
    RefPtr<nsDocument> mDisplayDocument;
    nsCOMPtr<nsIStreamListener> mTargetListener;
    nsCOMPtr<nsIURI> mURI;
  };
  friend class PendingLoad;

  class LoadgroupCallbacks final : public nsIInterfaceRequestor
  {
    ~LoadgroupCallbacks() {}
  public:
    explicit LoadgroupCallbacks(nsIInterfaceRequestor* aOtherCallbacks)
      : mCallbacks(aOtherCallbacks)
    {}
    NS_DECL_ISUPPORTS
    NS_DECL_NSIINTERFACEREQUESTOR
  private:
    // The only reason it's safe to hold a strong ref here without leaking is
    // that the notificationCallbacks on a loadgroup aren't the docshell itself
    // but a shim that holds a weak reference to the docshell.
    nsCOMPtr<nsIInterfaceRequestor> mCallbacks;

    // Use shims for interfaces that docshell implements directly so that we
    // don't hand out references to the docshell.  The shims should all allow
    // getInterface back on us, but other than that each one should only
    // implement one interface.

    // XXXbz I wish we could just derive the _allcaps thing from _i
#define DECL_SHIM(_i, _allcaps)                                              \
    class _i##Shim final : public nsIInterfaceRequestor,                     \
                           public _i                                         \
    {                                                                        \
      ~_i##Shim() {}                                                         \
    public:                                                                  \
      _i##Shim(nsIInterfaceRequestor* aIfreq, _i* aRealPtr)                  \
        : mIfReq(aIfreq), mRealPtr(aRealPtr)                                 \
      {                                                                      \
        NS_ASSERTION(mIfReq, "Expected non-null here");                      \
        NS_ASSERTION(mRealPtr, "Expected non-null here");                    \
      }                                                                      \
      NS_DECL_ISUPPORTS                                                      \
      NS_FORWARD_NSIINTERFACEREQUESTOR(mIfReq->)                             \
      NS_FORWARD_##_allcaps(mRealPtr->)                                      \
    private:                                                                 \
      nsCOMPtr<nsIInterfaceRequestor> mIfReq;                                \
      nsCOMPtr<_i> mRealPtr;                                                 \
    };

    DECL_SHIM(nsILoadContext, NSILOADCONTEXT)
    DECL_SHIM(nsIProgressEventSink, NSIPROGRESSEVENTSINK)
    DECL_SHIM(nsIChannelEventSink, NSICHANNELEVENTSINK)
    DECL_SHIM(nsISecurityEventSink, NSISECURITYEVENTSINK)
    DECL_SHIM(nsIApplicationCacheContainer, NSIAPPLICATIONCACHECONTAINER)
#undef DECL_SHIM
  };

  /**
   * Add an ExternalResource for aURI.  aViewer and aLoadGroup might be null
   * when this is called if the URI didn't result in an XML document.  This
   * function makes sure to remove the pending load for aURI, if any, from our
   * hashtable, and to notify its observers, if any.
   */
  nsresult AddExternalResource(nsIURI* aURI, nsIContentViewer* aViewer,
                               nsILoadGroup* aLoadGroup,
                               nsIDocument* aDisplayDocument);

  nsClassHashtable<nsURIHashKey, ExternalResource> mMap;
  nsRefPtrHashtable<nsURIHashKey, PendingLoad> mPendingLoads;
  bool mHaveShutDown;
};

// Base class for our document implementations.
class nsDocument : public nsIDocument,
                   public nsIDOMDocument,
                   public nsIDOMDocumentXBL,
                   public nsSupportsWeakReference,
                   public nsIScriptObjectPrincipal,
                   public nsIRadioGroupContainer,
                   public nsIApplicationCacheContainer,
                   public nsStubMutationObserver,
                   public nsIObserver,
                   public nsIDOMXPathEvaluator
{
  friend class nsIDocument;

public:
  typedef mozilla::dom::Element Element;
  using nsIDocument::GetElementsByTagName;
  typedef mozilla::net::ReferrerPolicy ReferrerPolicy;

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_SIZEOF_EXCLUDING_THIS

  virtual void Reset(nsIChannel *aChannel, nsILoadGroup *aLoadGroup) override;
  virtual void ResetToURI(nsIURI *aURI, nsILoadGroup *aLoadGroup,
                          nsIPrincipal* aPrincipal) override;

  // StartDocumentLoad is pure virtual so that subclasses must override it.
  // The nsDocument StartDocumentLoad does some setup, but does NOT set
  // *aDocListener; this is the job of subclasses.
  virtual nsresult StartDocumentLoad(const char* aCommand,
                                     nsIChannel* aChannel,
                                     nsILoadGroup* aLoadGroup,
                                     nsISupports* aContainer,
                                     nsIStreamListener **aDocListener,
                                     bool aReset = true,
                                     nsIContentSink* aContentSink = nullptr) override = 0;

  virtual void StopDocumentLoad() override;

  virtual void NotifyPossibleTitleChange(bool aBoundTitleElement) override;

  virtual void SetDocumentURI(nsIURI* aURI) override;

  virtual void SetChromeXHRDocURI(nsIURI* aURI) override;

  virtual void SetChromeXHRDocBaseURI(nsIURI* aURI) override;

  virtual void ApplySettingsFromCSP(bool aSpeculative) override;

  /**
   * Set the principal responsible for this document.
   */
  virtual void SetPrincipal(nsIPrincipal *aPrincipal) override;

  /**
   * Get the Content-Type of this document.
   */
  // NS_IMETHOD GetContentType(nsAString& aContentType);
  // Already declared in nsIDOMDocument

  /**
   * Set the Content-Type of this document.
   */
  virtual void SetContentType(const nsAString& aContentType) override;

  virtual void SetBaseURI(nsIURI* aURI) override;

  /**
   * Get/Set the base target of a link in a document.
   */
  virtual void GetBaseTarget(nsAString &aBaseTarget) override;

  /**
   * Return a standard name for the document's character set. This will
   * trigger a startDocumentLoad if necessary to answer the question.
   */
  virtual void SetDocumentCharacterSet(const nsACString& aCharSetID) override;

  /**
   * Add an observer that gets notified whenever the charset changes.
   */
  virtual nsresult AddCharSetObserver(nsIObserver* aObserver) override;

  /**
   * Remove a charset observer.
   */
  virtual void RemoveCharSetObserver(nsIObserver* aObserver) override;

  virtual Element* AddIDTargetObserver(nsIAtom* aID, IDTargetObserver aObserver,
                                       void* aData, bool aForImage) override;
  virtual void RemoveIDTargetObserver(nsIAtom* aID, IDTargetObserver aObserver,
                                      void* aData, bool aForImage) override;

  /**
   * Access HTTP header data (this may also get set from other sources, like
   * HTML META tags).
   */
  virtual void GetHeaderData(nsIAtom* aHeaderField, nsAString& aData) const override;
  virtual void SetHeaderData(nsIAtom* aheaderField,
                             const nsAString& aData) override;

  /**
   * Create a new presentation shell that will use aContext for
   * its presentation context (presentation contexts <b>must not</b> be
   * shared among multiple presentation shells).
   */
  virtual already_AddRefed<nsIPresShell> CreateShell(
      nsPresContext* aContext,
      nsViewManager* aViewManager,
      mozilla::StyleSetHandle aStyleSet) override;
  virtual void DeleteShell() override;

  virtual nsresult GetAllowPlugins(bool* aAllowPlugins) override;

  static bool IsElementAnimateEnabled(JSContext* aCx, JSObject* aObject);
  static bool IsWebAnimationsEnabled(JSContext* aCx, JSObject* aObject);
  virtual mozilla::dom::DocumentTimeline* Timeline() override;
  virtual void GetAnimations(
      nsTArray<RefPtr<mozilla::dom::Animation>>& aAnimations) override;
  mozilla::LinkedList<mozilla::dom::DocumentTimeline>& Timelines() override
  {
    return mTimelines;
  }

  virtual nsresult SetSubDocumentFor(Element* aContent,
                                     nsIDocument* aSubDoc) override;
  virtual nsIDocument* GetSubDocumentFor(nsIContent* aContent) const override;
  virtual Element* FindContentForSubDocument(nsIDocument *aDocument) const override;
  virtual Element* GetRootElementInternal() const override;

  virtual void EnsureOnDemandBuiltInUASheet(mozilla::StyleSheet* aSheet) override;

  virtual void AddStyleSheet(mozilla::StyleSheet* aSheet) override;
  virtual void RemoveStyleSheet(mozilla::StyleSheet* aSheet) override;

  virtual void UpdateStyleSheets(
      nsTArray<RefPtr<mozilla::StyleSheet>>& aOldSheets,
      nsTArray<RefPtr<mozilla::StyleSheet>>& aNewSheets) override;
  virtual void AddStyleSheetToStyleSets(mozilla::StyleSheet* aSheet);
  virtual void RemoveStyleSheetFromStyleSets(mozilla::StyleSheet* aSheet);

  virtual void InsertStyleSheetAt(mozilla::StyleSheet* aSheet,
                                  size_t aIndex) override;
  virtual void SetStyleSheetApplicableState(mozilla::StyleSheet* aSheet,
                                            bool aApplicable) override;

  virtual nsresult LoadAdditionalStyleSheet(additionalSheetType aType,
                                            nsIURI* aSheetURI) override;
  virtual nsresult AddAdditionalStyleSheet(additionalSheetType aType,
                                           mozilla::StyleSheet* aSheet) override;
  virtual void RemoveAdditionalStyleSheet(additionalSheetType aType,
                                          nsIURI* sheetURI) override;
  virtual mozilla::StyleSheet* GetFirstAdditionalAuthorSheet() override;

  virtual nsIChannel* GetChannel() const override {
    return mChannel;
  }

  virtual nsIChannel* GetFailedChannel() const override {
    return mFailedChannel;
  }
  virtual void SetFailedChannel(nsIChannel* aChannel) override {
    mFailedChannel = aChannel;
  }

  virtual void SetScriptGlobalObject(nsIScriptGlobalObject* aGlobalObject) override;

  virtual void SetScriptHandlingObject(nsIScriptGlobalObject* aScriptObject) override;

  virtual nsIGlobalObject* GetScopeObject() const override;
  void SetScopeObject(nsIGlobalObject* aGlobal) override;
  /**
   * Get the script loader for this document
   */
  virtual nsScriptLoader* ScriptLoader() override;

  /**
   * Add/Remove an element to the document's id and name hashes
   */
  virtual void AddToIdTable(Element* aElement, nsIAtom* aId) override;
  virtual void RemoveFromIdTable(Element* aElement, nsIAtom* aId) override;
  virtual void AddToNameTable(Element* aElement, nsIAtom* aName) override;
  virtual void RemoveFromNameTable(Element* aElement, nsIAtom* aName) override;

  /**
   * Add a new observer of document change notifications. Whenever
   * content is changed, appended, inserted or removed the observers are
   * informed.
   */
  virtual void AddObserver(nsIDocumentObserver* aObserver) override;

  /**
   * Remove an observer of document change notifications. This will
   * return false if the observer cannot be found.
   */
  virtual bool RemoveObserver(nsIDocumentObserver* aObserver) override;

  // Observation hooks used to propagate notifications to document
  // observers.
  virtual void BeginUpdate(nsUpdateType aUpdateType) override;
  virtual void EndUpdate(nsUpdateType aUpdateType) override;
  virtual void BeginLoad() override;
  virtual void EndLoad() override;

  // Set the readystate of the document. If updateTimingInformation is true,
  // this will record relevant timestamps in the document's performance timing.
  // Some consumers like document.open() don't want to do that.
  virtual void SetReadyStateInternal(ReadyState rs,
                                     bool updateTimingInformation = true) override;

  virtual void ContentStateChanged(nsIContent* aContent,
                                   mozilla::EventStates aStateMask)
                                     override;
  virtual void DocumentStatesChanged(
                 mozilla::EventStates aStateMask) override;

  virtual void StyleRuleChanged(mozilla::StyleSheet* aStyleSheet,
                                mozilla::css::Rule* aStyleRule) override;
  virtual void StyleRuleAdded(mozilla::StyleSheet* aStyleSheet,
                              mozilla::css::Rule* aStyleRule) override;
  virtual void StyleRuleRemoved(mozilla::StyleSheet* aStyleSheet,
                                mozilla::css::Rule* aStyleRule) override;

  virtual void FlushPendingNotifications(mozFlushType aType) override;
  virtual void FlushExternalResources(mozFlushType aType) override;
  virtual void SetXMLDeclaration(const char16_t *aVersion,
                                 const char16_t *aEncoding,
                                 const int32_t aStandalone) override;
  virtual void GetXMLDeclaration(nsAString& aVersion,
                                 nsAString& aEncoding,
                                 nsAString& Standalone) override;
  virtual bool IsScriptEnabled() override;

  virtual void OnPageShow(bool aPersisted, mozilla::dom::EventTarget* aDispatchStartTarget) override;
  virtual void OnPageHide(bool aPersisted, mozilla::dom::EventTarget* aDispatchStartTarget) override;

  virtual void WillDispatchMutationEvent(nsINode* aTarget) override;
  virtual void MutationEventDispatched(nsINode* aTarget) override;

  // nsINode
  virtual bool IsNodeOfType(uint32_t aFlags) const override;
  virtual nsIContent *GetChildAt(uint32_t aIndex) const override;
  virtual nsIContent * const * GetChildArray(uint32_t* aChildCount) const override;
  virtual int32_t IndexOf(const nsINode* aPossibleChild) const override;
  virtual uint32_t GetChildCount() const override;
  virtual nsresult InsertChildAt(nsIContent* aKid, uint32_t aIndex,
                                 bool aNotify) override;
  virtual void RemoveChildAt(uint32_t aIndex, bool aNotify) override;
  virtual nsresult Clone(mozilla::dom::NodeInfo *aNodeInfo, nsINode **aResult) const override
  {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  // nsIRadioGroupContainer
  NS_IMETHOD WalkRadioGroup(const nsAString& aName,
                            nsIRadioVisitor* aVisitor,
                            bool aFlushContent) override;
  virtual void
    SetCurrentRadioButton(const nsAString& aName,
                          mozilla::dom::HTMLInputElement* aRadio) override;
  virtual mozilla::dom::HTMLInputElement*
    GetCurrentRadioButton(const nsAString& aName) override;
  NS_IMETHOD
    GetNextRadioButton(const nsAString& aName,
                       const bool aPrevious,
                       mozilla::dom::HTMLInputElement*  aFocusedRadio,
                       mozilla::dom::HTMLInputElement** aRadioOut) override;
  virtual void AddToRadioGroup(const nsAString& aName,
                               nsIFormControl* aRadio) override;
  virtual void RemoveFromRadioGroup(const nsAString& aName,
                                    nsIFormControl* aRadio) override;
  virtual uint32_t GetRequiredRadioCount(const nsAString& aName) const override;
  virtual void RadioRequiredWillChange(const nsAString& aName,
                                       bool aRequiredAdded) override;
  virtual bool GetValueMissingState(const nsAString& aName) const override;
  virtual void SetValueMissingState(const nsAString& aName, bool aValue) override;

  // for radio group
  nsRadioGroupStruct* GetRadioGroup(const nsAString& aName) const;
  nsRadioGroupStruct* GetOrCreateRadioGroup(const nsAString& aName);

  virtual nsViewportInfo GetViewportInfo(const mozilla::ScreenIntSize& aDisplaySize) override;

  virtual void AddIntersectionObserver(
    mozilla::dom::DOMIntersectionObserver* aObserver) override;
  virtual void RemoveIntersectionObserver(
    mozilla::dom::DOMIntersectionObserver* aObserver) override;
  virtual void UpdateIntersectionObservations() override;
  virtual void ScheduleIntersectionObserverNotification() override;
  virtual void NotifyIntersectionObservers() override;

  virtual void NotifyLayerManagerRecreated() override;

private:
  void AddOnDemandBuiltInUASheet(mozilla::StyleSheet* aSheet);
  nsRadioGroupStruct* GetRadioGroupInternal(const nsAString& aName) const;
  void SendToConsole(nsCOMArray<nsISecurityConsoleMessage>& aMessages);

public:
  // nsIDOMNode
  NS_FORWARD_NSIDOMNODE_TO_NSINODE_OVERRIDABLE

  // nsIDOMDocument
  NS_DECL_NSIDOMDOCUMENT

  // nsIDOMDocumentXBL
  NS_DECL_NSIDOMDOCUMENTXBL

  // nsIDOMEventTarget
  virtual nsresult GetEventTargetParent(
                     mozilla::EventChainPreVisitor& aVisitor) override;
  virtual mozilla::EventListenerManager*
    GetOrCreateListenerManager() override;
  virtual mozilla::EventListenerManager*
    GetExistingListenerManager() const override;

  // nsIScriptObjectPrincipal
  virtual nsIPrincipal* GetPrincipal() override;

  // nsIApplicationCacheContainer
  NS_DECL_NSIAPPLICATIONCACHECONTAINER

  // nsIObserver
  NS_DECL_NSIOBSERVER

  NS_DECL_NSIDOMXPATHEVALUATOR

  virtual nsresult Init();

  virtual already_AddRefed<Element> CreateElem(const nsAString& aName,
                                               nsIAtom* aPrefix,
                                               int32_t aNamespaceID,
                                               const nsAString* aIs = nullptr) override;

  virtual void Sanitize() override;

  virtual void EnumerateSubDocuments(nsSubDocEnumFunc aCallback,
                                                 void *aData) override;

  virtual bool CanSavePresentation(nsIRequest *aNewRequest) override;
  virtual void Destroy() override;
  virtual void RemovedFromDocShell() override;
  virtual already_AddRefed<nsILayoutHistoryState> GetLayoutHistoryState() const override;

  virtual void BlockOnload() override;
  virtual void UnblockOnload(bool aFireSync) override;

  virtual void AddStyleRelevantLink(mozilla::dom::Link* aLink) override;
  virtual void ForgetLink(mozilla::dom::Link* aLink) override;

  virtual void ClearBoxObjectFor(nsIContent* aContent) override;

  virtual already_AddRefed<mozilla::dom::BoxObject>
  GetBoxObjectFor(mozilla::dom::Element* aElement,
                  mozilla::ErrorResult& aRv) override;

  virtual Element*
    GetAnonymousElementByAttribute(nsIContent* aElement,
                                   nsIAtom* aAttrName,
                                   const nsAString& aAttrValue) const override;

  virtual Element* ElementFromPointHelper(float aX, float aY,
                                          bool aIgnoreRootScrollFrame,
                                          bool aFlushLayout) override;

  virtual void ElementsFromPointHelper(float aX, float aY,
                                       uint32_t aFlags,
                                       nsTArray<RefPtr<mozilla::dom::Element>>& aElements) override;

  virtual nsresult NodesFromRectHelper(float aX, float aY,
                                                   float aTopSize, float aRightSize,
                                                   float aBottomSize, float aLeftSize,
                                                   bool aIgnoreRootScrollFrame,
                                                   bool aFlushLayout,
                                                   nsIDOMNodeList** aReturn) override;

  virtual void FlushSkinBindings() override;

  virtual nsresult InitializeFrameLoader(nsFrameLoader* aLoader) override;
  virtual nsresult FinalizeFrameLoader(nsFrameLoader* aLoader, nsIRunnable* aFinalizer) override;
  virtual void TryCancelFrameLoaderInitialization(nsIDocShell* aShell) override;
  virtual nsIDocument*
    RequestExternalResource(nsIURI* aURI,
                            nsINode* aRequestingNode,
                            ExternalResourceLoad** aPendingLoad) override;
  virtual void
    EnumerateExternalResources(nsSubDocEnumFunc aCallback, void* aData) override;

  // Returns our (lazily-initialized) animation controller.
  // If HasAnimationController is true, this is guaranteed to return non-null.
  nsSMILAnimationController* GetAnimationController() override;

  virtual mozilla::PendingAnimationTracker*
  GetPendingAnimationTracker() final override
  {
    return mPendingAnimationTracker;
  }

  virtual mozilla::PendingAnimationTracker*
  GetOrCreatePendingAnimationTracker() override;

  virtual void SuppressEventHandling(SuppressionType aWhat,
                                     uint32_t aIncrease) override;

  virtual void UnsuppressEventHandlingAndFireEvents(SuppressionType aWhat,
                                                    bool aFireEvents) override;

  void DecreaseEventSuppression() {
    MOZ_ASSERT(mEventsSuppressed);
    --mEventsSuppressed;
    UpdateFrameRequestCallbackSchedulingState();
  }

  void ResumeAnimations() {
    MOZ_ASSERT(mAnimationsPaused);
    --mAnimationsPaused;
    UpdateFrameRequestCallbackSchedulingState();
  }

  void SetLoadEventFiring(bool aFiring) override { mLoadEventFiring = aFiring; }

  bool SkipLoadEventAfterClose() override {
    bool skip = mSkipLoadEventAfterClose;
    mSkipLoadEventAfterClose = false;
    return skip;
  }

  virtual nsIDocument* GetTemplateContentsOwner() override;

  NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_AMBIGUOUS(nsDocument,
                                                                   nsIDocument)

  void DoNotifyPossibleTitleChange();

  nsExternalResourceMap& ExternalResourceMap()
  {
    return mExternalResourceMap;
  }

  void SetLoadedAsData(bool aLoadedAsData) { mLoadedAsData = aLoadedAsData; }
  void SetLoadedAsInteractiveData(bool aLoadedAsInteractiveData)
  {
    mLoadedAsInteractiveData = aLoadedAsInteractiveData;
  }

  nsresult CloneDocHelper(nsDocument* clone) const;

  void MaybeInitializeFinalizeFrameLoaders();

  void MaybeEndOutermostXBLUpdate();

  virtual void PreloadPictureOpened() override;
  virtual void PreloadPictureClosed() override;

  virtual void
    PreloadPictureImageSource(const nsAString& aSrcsetAttr,
                              const nsAString& aSizesAttr,
                              const nsAString& aTypeAttr,
                              const nsAString& aMediaAttr) override;

  virtual already_AddRefed<nsIURI>
    ResolvePreloadImage(nsIURI *aBaseURI,
                        const nsAString& aSrcAttr,
                        const nsAString& aSrcsetAttr,
                        const nsAString& aSizesAttr,
                        bool *aIsImgSet) override;

  virtual void MaybePreLoadImage(nsIURI* uri,
                                 const nsAString &aCrossOriginAttr,
                                 ReferrerPolicy aReferrerPolicy,
                                 bool aIsImgSet) override;
  virtual void ForgetImagePreload(nsIURI* aURI) override;

  virtual void MaybePreconnect(nsIURI* uri,
                               mozilla::CORSMode aCORSMode) override;

  virtual void PreloadStyle(nsIURI* uri, const nsAString& charset,
                            const nsAString& aCrossOriginAttr,
                            ReferrerPolicy aReferrerPolicy,
                            const nsAString& aIntegrity) override;

  virtual nsresult LoadChromeSheetSync(nsIURI* uri, bool isAgentSheet,
                                       RefPtr<mozilla::StyleSheet>* aSheet) override;

  virtual nsISupports* GetCurrentContentSink() override;

  virtual mozilla::EventStates GetDocumentState() override;

  // Only BlockOnload should call this!
  void AsyncBlockOnload();

  virtual void SetScrollToRef(nsIURI *aDocumentURI) override;
  virtual void ScrollToRef() override;
  virtual void ResetScrolledToRefAlready() override;
  virtual void SetChangeScrollPosWhenScrollingToRef(bool aValue) override;

  virtual Element *GetElementById(const nsAString& aElementId) override;
  virtual const nsTArray<Element*>* GetAllElementsForId(const nsAString& aElementId) const override;

  virtual Element *LookupImageElement(const nsAString& aElementId) override;
  virtual void MozSetImageElement(const nsAString& aImageElementId,
                                  Element* aElement) override;

  // AddPlugin adds a plugin-related element to mPlugins when the element is
  // added to the tree.
  virtual nsresult AddPlugin(nsIObjectLoadingContent* aPlugin) override;
  // RemovePlugin removes a plugin-related element to mPlugins when the
  // element is removed from the tree.
  virtual void RemovePlugin(nsIObjectLoadingContent* aPlugin) override;
  // GetPlugins returns the plugin-related elements from
  // the frame and any subframes.
  virtual void GetPlugins(nsTArray<nsIObjectLoadingContent*>& aPlugins) override;

  // Adds an element to mResponsiveContent when the element is
  // added to the tree.
  virtual nsresult AddResponsiveContent(nsIContent* aContent) override;
  // Removes an element from mResponsiveContent when the element is
  // removed from the tree.
  virtual void RemoveResponsiveContent(nsIContent* aContent) override;
  // Notifies any responsive content added by AddResponsiveContent upon media
  // features values changing.
  virtual void NotifyMediaFeatureValuesChanged() override;

  virtual nsresult GetStateObject(nsIVariant** aResult) override;

  virtual nsDOMNavigationTiming* GetNavigationTiming() const override;
  virtual nsresult SetNavigationTiming(nsDOMNavigationTiming* aTiming) override;

  virtual Element* FindImageMap(const nsAString& aNormalizedMapName) override;

  virtual nsTArray<Element*> GetFullscreenStack() const override;
  virtual void AsyncRequestFullScreen(
    mozilla::UniquePtr<FullscreenRequest>&& aRequest) override;
  virtual void RestorePreviousFullScreenState() override;
  virtual bool IsFullscreenLeaf() override;
  virtual nsresult
    RemoteFrameFullscreenChanged(nsIDOMElement* aFrameElement) override;

  virtual nsresult RemoteFrameFullscreenReverted() override;
  virtual nsIDocument* GetFullscreenRoot() override;
  virtual void SetFullscreenRoot(nsIDocument* aRoot) override;

  // Returns the size of the mBlockedTrackingNodes array. (nsIDocument.h)
  //
  // This array contains nodes that have been blocked to prevent
  // user tracking. They most likely have had their nsIChannel
  // canceled by the URL classifier (Safebrowsing).
  //
  // A script can subsequently use GetBlockedTrackingNodes()
  // to get a list of references to these nodes.
  //
  // Note:
  // This expresses how many tracking nodes have been blocked for this
  // document since its beginning, not how many of them are still around
  // in the DOM tree. Weak references to blocked nodes are added in the
  // mBlockedTrackingNodesArray but they are not removed when those nodes
  // are removed from the tree or even garbage collected.
  long BlockedTrackingNodeCount() const;

  //
  // Returns strong references to mBlockedTrackingNodes. (nsIDocument.h)
  //
  // This array contains nodes that have been blocked to prevent
  // user tracking. They most likely have had their nsIChannel
  // canceled by the URL classifier (Safebrowsing).
  //
  already_AddRefed<nsSimpleContentList> BlockedTrackingNodes() const;

  static bool IsUnprefixedFullscreenEnabled(JSContext* aCx, JSObject* aObject);

  // Do the "fullscreen element ready check" from the fullscreen spec.
  // It returns true if the given element is allowed to go into fullscreen.
  bool FullscreenElementReadyCheck(Element* aElement, bool aWasCallerChrome);

  // This is called asynchronously by nsIDocument::AsyncRequestFullScreen()
  // to move this document into full-screen mode if allowed.
  void RequestFullScreen(mozilla::UniquePtr<FullscreenRequest>&& aRequest);

  // Removes all elements from the full-screen stack, removing full-scren
  // styles from the top element in the stack.
  void CleanupFullscreenState();

  // Pushes aElement onto the full-screen stack, and removes full-screen styles
  // from the former full-screen stack top, and its ancestors, and applies the
  // styles to aElement. aElement becomes the new "full-screen element".
  bool FullScreenStackPush(Element* aElement);

  // Remove the top element from the full-screen stack. Removes the full-screen
  // styles from the former top element, and applies them to the new top
  // element, if there is one.
  void FullScreenStackPop();

  // Returns the top element from the full-screen stack.
  Element* FullScreenStackTop();

  // DOM-exposed fullscreen API
  bool FullscreenEnabled() override;
  Element* GetFullscreenElement() override;

  void RequestPointerLock(Element* aElement) override;
  bool SetPointerLock(Element* aElement, int aCursorStyle);
  static void UnlockPointer(nsIDocument* aDoc = nullptr);

  void SetCurrentOrientation(mozilla::dom::OrientationType aType,
                             uint16_t aAngle) override;
  uint16_t CurrentOrientationAngle() const override;
  mozilla::dom::OrientationType CurrentOrientationType() const override;
  void SetOrientationPendingPromise(mozilla::dom::Promise* aPromise) override;
  mozilla::dom::Promise* GetOrientationPendingPromise() const override;

  // This method may fire a DOM event; if it does so it will happen
  // synchronously.
  void UpdateVisibilityState();
  // Posts an event to call UpdateVisibilityState
  virtual void PostVisibilityUpdateEvent() override;

  // Since we wouldn't automatically play media from non-visited page, we need
  // to notify window when the page was first visited.
  void MaybeActiveMediaComponents();

  virtual void DocAddSizeOfExcludingThis(nsWindowSizes* aWindowSizes) const override;
  // DocAddSizeOfIncludingThis is inherited from nsIDocument.

  virtual nsIDOMNode* AsDOMNode() override { return this; }

  // WebIDL bits
  virtual mozilla::dom::DOMImplementation*
    GetImplementation(mozilla::ErrorResult& rv) override;

  virtual void SetSelectedStyleSheetSet(const nsAString& aSheetSet) override;
  virtual void GetLastStyleSheetSet(nsString& aSheetSet) override;
  virtual mozilla::dom::DOMStringList* StyleSheetSets() override;
  virtual void EnableStyleSheetsForSet(const nsAString& aSheetSet) override;
  virtual already_AddRefed<Element> CreateElement(const nsAString& aTagName,
                                                  const mozilla::dom::ElementCreationOptionsOrString& aOptions,
                                                  ErrorResult& rv) override;
  virtual already_AddRefed<Element> CreateElementNS(const nsAString& aNamespaceURI,
                                                    const nsAString& aQualifiedName,
                                                    const mozilla::dom::ElementCreationOptionsOrString& aOptions,
                                                    mozilla::ErrorResult& rv) override;

  virtual nsIDocument* MasterDocument() override
  {
    return mMasterDocument ? mMasterDocument.get()
                           : this;
  }

  virtual void SetMasterDocument(nsIDocument* master) override
  {
    MOZ_ASSERT(master);
    mMasterDocument = master;
  }

  virtual bool IsMasterDocument() override
  {
    return !mMasterDocument;
  }

  virtual mozilla::dom::ImportManager* ImportManager() override
  {
    if (mImportManager) {
      MOZ_ASSERT(!mMasterDocument, "Only the master document has ImportManager set");
      return mImportManager.get();
    }

    if (mMasterDocument) {
      return mMasterDocument->ImportManager();
    }

    // ImportManager is created lazily.
    // If the manager is not yet set it has to be the
    // master document and this is the first import in it.
    // Let's create a new manager.
    mImportManager = new mozilla::dom::ImportManager();
    return mImportManager.get();
  }

  virtual bool HasSubImportLink(nsINode* aLink) override
  {
    return mSubImportLinks.Contains(aLink);
  }

  virtual uint32_t IndexOfSubImportLink(nsINode* aLink) override
  {
    return mSubImportLinks.IndexOf(aLink);
  }

  virtual void AddSubImportLink(nsINode* aLink) override
  {
    mSubImportLinks.AppendElement(aLink);
  }

  virtual nsINode* GetSubImportLink(uint32_t aIdx) override
  {
    return aIdx < mSubImportLinks.Length() ? mSubImportLinks[aIdx].get()
                                           : nullptr;
  }

  virtual void UnblockDOMContentLoaded() override;

protected:
  friend class nsNodeUtils;
  friend class nsDocumentOnStack;

  void IncreaseStackRefCnt()
  {
    ++mStackRefCnt;
  }

  void DecreaseStackRefCnt()
  {
    if (--mStackRefCnt == 0 && mNeedsReleaseAfterStackRefCntRelease) {
      mNeedsReleaseAfterStackRefCntRelease = false;
      NS_RELEASE_THIS();
    }
  }

  /**
   * Check that aId is not empty and log a message to the console
   * service if it is.
   * @returns true if aId looks correct, false otherwise.
   */
  inline bool CheckGetElementByIdArg(const nsAString& aId)
  {
    if (aId.IsEmpty()) {
      ReportEmptyGetElementByIdArg();
      return false;
    }
    return true;
  }

  void ReportEmptyGetElementByIdArg();

  void DispatchContentLoadedEvents();

  void RetrieveRelevantHeaders(nsIChannel *aChannel);

  void TryChannelCharset(nsIChannel *aChannel,
                         int32_t& aCharsetSource,
                         nsACString& aCharset,
                         nsHtml5TreeOpExecutor* aExecutor);

  // Call this before the document does something that will unbind all content.
  // That will stop us from doing a lot of work as each element is removed.
  void DestroyElementMaps();

  // Refreshes the hrefs of all the links in the document.
  void RefreshLinkHrefs();

  nsIContent* GetFirstBaseNodeWithHref();
  nsresult SetFirstBaseNodeWithHref(nsIContent *node);

  /**
   * Returns the title element of the document as defined by the HTML
   * specification, or null if there isn't one.  For documents whose root
   * element is an <svg:svg>, this is the first <svg:title> element that's a
   * child of the root.  For other documents, it's the first HTML title element
   * in the document.
   */
  Element* GetTitleElement();

  /**
   * Perform tree disconnection needed by ResetToURI and document.open()
   */
  void DisconnectNodeTree();

public:
  // Get our title
  virtual void GetTitle(nsString& aTitle) override;
  // Set our title
  virtual void SetTitle(const nsAString& aTitle, mozilla::ErrorResult& rv) override;

  bool mIsTopLevelContentDocument: 1;
  bool mIsContentDocument: 1;

  bool IsTopLevelContentDocument();
  void SetIsTopLevelContentDocument(bool aIsTopLevelContentDocument);

  bool IsContentDocument() const;
  void SetIsContentDocument(bool aIsContentDocument);

  js::ExpandoAndGeneration mExpandoAndGeneration;

#ifdef MOZ_EME
  bool ContainsEMEContent();
#endif

  bool ContainsMSEContent();

protected:
  already_AddRefed<nsIPresShell> doCreateShell(nsPresContext* aContext,
                                               nsViewManager* aViewManager,
                                               mozilla::StyleSetHandle aStyleSet);

  void RemoveDocStyleSheetsFromStyleSets();
  void RemoveStyleSheetsFromStyleSets(
      const nsTArray<RefPtr<mozilla::StyleSheet>>& aSheets,
      mozilla::SheetType aType);
  void ResetStylesheetsToURI(nsIURI* aURI);
  void FillStyleSet(mozilla::StyleSetHandle aStyleSet);

  // Return whether all the presshells for this document are safe to flush
  bool IsSafeToFlush() const;

  void DispatchPageTransition(mozilla::dom::EventTarget* aDispatchTarget,
                              const nsAString& aType,
                              bool aPersisted);

  virtual nsPIDOMWindowOuter* GetWindowInternal() const override;
  virtual nsIScriptGlobalObject* GetScriptHandlingObjectInternal() const override;
  virtual bool InternalAllowXULXBL() override;

  void UpdateScreenOrientation();

#define NS_DOCUMENT_NOTIFY_OBSERVERS(func_, params_)                        \
  NS_OBSERVER_ARRAY_NOTIFY_XPCOM_OBSERVERS(mObservers, nsIDocumentObserver, \
                                           func_, params_);

#ifdef DEBUG
  void VerifyRootContentState();
#endif

  explicit nsDocument(const char* aContentType);
  virtual ~nsDocument();

  void EnsureOnloadBlocker();

  void NotifyStyleSheetApplicableStateChanged();

  // Apply the fullscreen state to the document, and trigger related
  // events. It returns false if the fullscreen element ready check
  // fails and nothing gets changed.
  bool ApplyFullscreen(const FullscreenRequest& aRequest);

  nsTArray<nsIObserver*> mCharSetObservers;

  PLDHashTable *mSubDocuments;

  // Array of owning references to all children
  nsAttrAndChildArray mChildren;

  // Pointer to our parser if we're currently in the process of being
  // parsed into.
  nsCOMPtr<nsIParser> mParser;

  // Weak reference to our sink for in case we no longer have a parser.  This
  // will allow us to flush out any pending stuff from the sink even if
  // EndLoad() has already happened.
  nsWeakPtr mWeakSink;

  nsTArray<RefPtr<mozilla::StyleSheet>> mOnDemandBuiltInUASheets;
  nsTArray<RefPtr<mozilla::StyleSheet>> mAdditionalSheets[AdditionalSheetTypeCount];

  // Array of observers
  nsTObserverArray<nsIDocumentObserver*> mObservers;

  // Hashtable of intersection observers
  nsTHashtable<nsPtrHashKey<mozilla::dom::DOMIntersectionObserver>>
    mIntersectionObservers;

  // Tracker for animations that are waiting to start.
  // nullptr until GetOrCreatePendingAnimationTracker is called.
  RefPtr<mozilla::PendingAnimationTracker> mPendingAnimationTracker;

  // Weak reference to the scope object (aka the script global object)
  // that, unlike mScriptGlobalObject, is never unset once set. This
  // is a weak reference to avoid leaks due to circular references.
  nsWeakPtr mScopeObject;

  // Stack of full-screen elements. When we request full-screen we push the
  // full-screen element onto this stack, and when we cancel full-screen we
  // pop one off this stack, restoring the previous full-screen state
  nsTArray<nsWeakPtr> mFullScreenStack;

  // The root of the doc tree in which this document is in. This is only
  // non-null when this document is in fullscreen mode.
  nsWeakPtr mFullscreenRoot;

public:
  // Check whether web components are enabled for the global of aObject.
  static bool IsWebComponentsEnabled(JSContext* aCx, JSObject* aObject);
  // Check whether web components are enabled for the document this node belongs
  // to.
  static bool IsWebComponentsEnabled(const nsINode* aNode);
  // Check whether web components are enabled for the global of the document
  // this nodeinfo comes from.
  static bool IsWebComponentsEnabled(mozilla::dom::NodeInfo* aNodeInfo);
  // Check whether web components are enabled for the given window.
  static bool IsWebComponentsEnabled(nsPIDOMWindowInner* aWindow);

  RefPtr<mozilla::EventListenerManager> mListenerManager;
  RefPtr<nsDOMStyleSheetSetList> mStyleSheetSetList;
  RefPtr<nsScriptLoader> mScriptLoader;
  nsDocHeaderData* mHeaderData;
  /* mIdentifierMap works as follows for IDs:
   * 1) Attribute changes affect the table immediately (removing and adding
   *    entries as needed).
   * 2) Removals from the DOM affect the table immediately
   * 3) Additions to the DOM always update existing entries for names, and add
   *    new ones for IDs.
   */
  nsTHashtable<nsIdentifierMapEntry> mIdentifierMap;

  nsClassHashtable<nsStringHashKey, nsRadioGroupStruct> mRadioGroups;

  // Recorded time of change to 'loading' state.
  mozilla::TimeStamp mLoadingTimeStamp;

  // True if the document has been detached from its content viewer.
  bool mIsGoingAway:1;
  // True if the document is being destroyed.
  bool mInDestructor:1;

  // True if this document has ever had an HTML or SVG <title> element
  // bound to it
  bool mMayHaveTitleElement:1;

  bool mHasWarnedAboutBoxObjects:1;

  bool mDelayFrameLoaderInitialization:1;

  bool mSynchronousDOMContentLoaded:1;

  bool mInXBLUpdate:1;

  // Whether we're currently under a FlushPendingNotifications call to
  // our presshell.  This is used to handle flush reentry correctly.
  bool mInFlush:1;

  // Parser aborted. True if the parser of this document was forcibly
  // terminated instead of letting it finish at its own pace.
  bool mParserAborted:1;

  friend class nsCallRequestFullScreen;

  // ScreenOrientation "pending promise" as described by
  // http://www.w3.org/TR/screen-orientation/
  RefPtr<mozilla::dom::Promise> mOrientationPendingPromise;

  uint16_t mCurrentOrientationAngle;
  mozilla::dom::OrientationType mCurrentOrientationType;

  // Keeps track of whether we have a pending
  // 'style-sheet-applicable-state-changed' notification.
  bool mSSApplicableStateNotificationPending:1;

  // Whether we have filled our pres shell's style set with the document's
  // additional sheets and sheets from the nsStyleSheetService.
  bool mStyleSetFilled:1;

  // The HTML spec has a "iframe load in progress" flag, but that doesn't seem
  // to have the right semantics. See <https://github.com/whatwg/html/issues/4292>.
  // What we have instead is a flag that is set while the window's 'load' event is
  // firing if this document is the window's document.
  bool mLoadEventFiring : 1;

  // The HTML spec has a "mute iframe load" flag, but that doesn't seem to have
  // the right semantics. See <https://github.com/whatwg/html/issues/4292>.
  // What we have instead is a flag that is set if completion of our document
  // via document.close() should skip firing the load event. Note that this
  // flag is only relevant for HTML documents, but lives here for reasons that
  // are documented above on SkipLoadEventAfterClose().
  bool mSkipLoadEventAfterClose : 1;

  uint8_t mPendingFullscreenRequests;

  uint8_t mXMLDeclarationBits;

  nsInterfaceHashtable<nsPtrHashKey<nsIContent>, nsPIBoxObject> *mBoxObjectTable;

  // A document "without a browsing context" that owns the content of
  // HTMLTemplateElement.
  nsCOMPtr<nsIDocument> mTemplateContentsOwner;

  // Our update nesting level
  uint32_t mUpdateNestLevel;

  // The application cache that this document is associated with, if
  // any.  This can change during the lifetime of the document.
  nsCOMPtr<nsIApplicationCache> mApplicationCache;

  nsCOMPtr<nsIContent> mFirstBaseNodeWithHref;

  mozilla::EventStates mDocumentState;
  mozilla::EventStates mGotDocumentState;

  RefPtr<nsDOMNavigationTiming> mTiming;
private:
  friend class nsUnblockOnloadEvent;
  // Recomputes the visibility state but doesn't set the new value.
  mozilla::dom::VisibilityState GetVisibilityState() const;
  void NotifyStyleSheetAdded(mozilla::StyleSheet* aSheet, bool aDocumentSheet);
  void NotifyStyleSheetRemoved(mozilla::StyleSheet* aSheet, bool aDocumentSheet);

  void PostUnblockOnloadEvent();
  void DoUnblockOnload();

  nsresult InitCSP(nsIChannel* aChannel);

  /**
   * Find the (non-anonymous) content in this document for aFrame. It will
   * be aFrame's content node if that content is in this document and not
   * anonymous. Otherwise, when aFrame is in a subdocument, we use the frame
   * element containing the subdocument containing aFrame, and/or find the
   * nearest non-anonymous ancestor in this document.
   * Returns null if there is no such element.
   */
  nsIContent* GetContentInThisDocument(nsIFrame* aFrame) const;

  // Just like EnableStyleSheetsForSet, but doesn't check whether
  // aSheetSet is null and allows the caller to control whether to set
  // aSheetSet as the preferred set in the CSSLoader.
  void EnableStyleSheetsForSetInternal(const nsAString& aSheetSet,
                                       bool aUpdateCSSLoader);

  void ClearAllBoxObjects();

  // Returns true if the scheme for the url for this document is "about"
  bool IsAboutPage();

  // These are not implemented and not supported.
  nsDocument(const nsDocument& aOther);
  nsDocument& operator=(const nsDocument& aOther);

  // The layout history state that should be used by nodes in this
  // document.  We only actually store a pointer to it when:
  // 1)  We have no script global object.
  // 2)  We haven't had Destroy() called on us yet.
  nsCOMPtr<nsILayoutHistoryState> mLayoutHistoryState;

  // Currently active onload blockers
  uint32_t mOnloadBlockCount;
  // Onload blockers which haven't been activated yet
  uint32_t mAsyncOnloadBlockCount;
  nsCOMPtr<nsIRequest> mOnloadBlocker;

  // A hashtable of styled links keyed by address pointer.
  nsTHashtable<nsPtrHashKey<mozilla::dom::Link> > mStyledLinks;
#ifdef DEBUG
  // Indicates whether mStyledLinks was cleared or not.  This is used to track
  // state so we can provide useful assertions to consumers of ForgetLink and
  // AddStyleRelevantLink.
  bool mStyledLinksCleared;
#endif

  // A set of responsive images keyed by address pointer.
  nsTHashtable< nsPtrHashKey<nsIContent> > mResponsiveContent;

  // Member to store out last-selected stylesheet set.
  nsString mLastStyleSheetSet;

  nsTArray<RefPtr<nsFrameLoader> > mInitializableFrameLoaders;
  nsTArray<nsCOMPtr<nsIRunnable> > mFrameLoaderFinalizers;
  RefPtr<nsRunnableMethod<nsDocument> > mFrameLoaderRunner;

  nsCOMPtr<nsIRunnable> mMaybeEndOutermostXBLUpdateRunner;

  nsRevocableEventPtr<nsRunnableMethod<nsDocument, void, false> >
    mPendingTitleChangeEvent;

  nsExternalResourceMap mExternalResourceMap;

  // All images in process of being preloaded.  This is a hashtable so
  // we can remove them as the real image loads start; that way we
  // make sure to not keep the image load going when no one cares
  // about it anymore.
  nsRefPtrHashtable<nsURIHashKey, imgIRequest> mPreloadingImages;

  // A list of preconnects initiated by the preloader. This prevents
  // the same uri from being used more than once, and allows the dom
  // builder to not repeat the work of the preloader.
  nsDataHashtable< nsURIHashKey, bool> mPreloadedPreconnects;

  // Current depth of picture elements from parser
  int32_t mPreloadPictureDepth;

  // Set if we've found a URL for the current picture
  nsString mPreloadPictureFoundSource;

  RefPtr<mozilla::dom::DOMImplementation> mDOMImplementation;

  RefPtr<nsContentList> mImageMaps;

  nsCString mScrollToRef;
  uint8_t mScrolledToRefAlready : 1;
  uint8_t mChangeScrollPosWhenScrollingToRef : 1;

  // Tracking for plugins in the document.
  nsTHashtable< nsPtrHashKey<nsIObjectLoadingContent> > mPlugins;

  RefPtr<mozilla::dom::DocumentTimeline> mDocumentTimeline;
  mozilla::LinkedList<mozilla::dom::DocumentTimeline> mTimelines;

  enum ViewportType {
    DisplayWidthHeight,
    Specified,
    Unknown
  };

  ViewportType mViewportType;

  // These member variables cache information about the viewport so we don't have to
  // recalculate it each time.
  bool mValidWidth, mValidHeight;
  mozilla::LayoutDeviceToScreenScale mScaleMinFloat;
  mozilla::LayoutDeviceToScreenScale mScaleMaxFloat;
  mozilla::LayoutDeviceToScreenScale mScaleFloat;
  mozilla::CSSToLayoutDeviceScale mPixelRatio;
  bool mAutoSize, mAllowZoom, mAllowDoubleTapZoom, mValidScaleFloat, mValidMaxScale, mScaleStrEmpty, mWidthStrEmpty;
  mozilla::CSSSize mViewportSize;

  nsrefcnt mStackRefCnt;
  bool mNeedsReleaseAfterStackRefCntRelease;

  nsCOMPtr<nsIDocument> mMasterDocument;
  RefPtr<mozilla::dom::ImportManager> mImportManager;
  nsTArray<nsCOMPtr<nsINode> > mSubImportLinks;

  // Set to true when the document is possibly controlled by the ServiceWorker.
  // Used to prevent multiple requests to ServiceWorkerManager.
  bool mMaybeServiceWorkerControlled;
};

class nsDocumentOnStack
{
public:
  explicit nsDocumentOnStack(nsDocument* aDoc) : mDoc(aDoc)
  {
    mDoc->IncreaseStackRefCnt();
  }
  ~nsDocumentOnStack()
  {
    mDoc->DecreaseStackRefCnt();
  }
private:
  nsDocument* mDoc;
};

#endif /* nsDocument_h___ */