Bug 1916311 - [css-view-transitions] Initial pass at DOM API internals. r=boris,webidl,smaug

This is still fairly incomplete (i.e. no capturing, etc), but it allows
a transition to "start", and then finish (on the next frame always, for
now) or timeout, appropriately.

I think it's in a reviewable shape, given that. There's one known
divergence from the spec, which is described in
w3c/csswg-drafts#10822

Differential Revision: https://phabricator.services.mozilla.com/D220843

UltraBlame original commit: cadf4f0266df277312b21c23e63fef2366d0518e

Author: marco-c

dom/base/Document.cpp

@@ -2259,6 +2259,17 @@ mozilla
 /
 dom
 /
+ViewTransition
+.
+h
+"
+#
+include
+"
+mozilla
+/
+dom
+/
 WakeLockJS
 .
 h
@@ -14359,6 +14370,10 @@ mAll
 )
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE
 (
+mActiveViewTransition
+)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE
+(
 mDocGroup
 )
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE
@@ -14982,6 +14997,10 @@ mAll
 )
 NS_IMPL_CYCLE_COLLECTION_UNLINK
 (
+mActiveViewTransition
+)
+NS_IMPL_CYCLE_COLLECTION_UNLINK
+(
 mReferrerInfo
 )
 NS_IMPL_CYCLE_COLLECTION_UNLINK
@@ -83971,8 +83990,10 @@ root
 ;
 }
 }
+already_AddRefed
+<
 ViewTransition
-*
+>
 Document
 :
 :
@@ -83987,12 +84008,176 @@ ViewTransitionUpdateCallback
 >
 >
 &
+aCallback
+)
+{
+RefPtr
+transition
+=
+new
+ViewTransition
+(
+*
+this
+aCallback
+.
+WasPassed
+(
+)
+?
+&
+aCallback
+.
+Value
+(
+)
+:
+nullptr
+)
+;
+if
+(
+Hidden
+(
+)
 )
 {
+transition
+-
+>
+SkipTransition
+(
+SkipTransitionReason
+:
+:
+DocumentHidden
+)
+;
 return
+transition
+.
+forget
+(
+)
+;
+}
+if
+(
+mActiveViewTransition
+)
+{
+mActiveViewTransition
+-
+>
+SkipTransition
+(
+SkipTransitionReason
+:
+:
+ClobberedActiveTransition
+)
+;
+}
+mActiveViewTransition
+=
+transition
+;
+if
+(
+mPresShell
+)
+{
+if
+(
+nsRefreshDriver
+*
+rd
+=
+mPresShell
+-
+>
+GetRefreshDriver
+(
+)
+)
+{
+rd
+-
+>
+EnsureViewTransitionOperationsHappen
+(
+)
+;
+}
+}
+return
+transition
+.
+forget
+(
+)
+;
+}
+void
+Document
+:
+:
+ClearActiveViewTransition
+(
+)
+{
+mActiveViewTransition
+=
 nullptr
 ;
 }
+void
+Document
+:
+:
+PerformPendingViewTransitionOperations
+(
+)
+{
+if
+(
+mActiveViewTransition
+)
+{
+mActiveViewTransition
+-
+>
+PerformPendingOperations
+(
+)
+;
+}
+EnumerateSubDocuments
+(
+[
+]
+(
+Document
+&
+aDoc
+)
+{
+aDoc
+.
+PerformPendingViewTransitionOperations
+(
+)
+;
+return
+CallState
+:
+:
+Continue
+;
+}
+)
+;
+}
 Selection
 *
 Document

dom/base/Document.h

@@ -11246,8 +11246,10 @@ DetermineProximityToViewportAndNotifyResizeObservers
 (
 )
 ;
+already_AddRefed
+<
 ViewTransition
-*
+>
 StartViewTransition
 (
 const
@@ -11261,6 +11263,27 @@ ViewTransitionUpdateCallback
 &
 )
 ;
+ViewTransition
+*
+GetActiveViewTransition
+(
+)
+const
+{
+return
+mActiveViewTransition
+;
+}
+void
+ClearActiveViewTransition
+(
+)
+;
+void
+PerformPendingViewTransitionOperations
+(
+)
+;
 PermissionDelegateHandler
 *
 GetPermissionDelegateHandler
@@ -14727,6 +14750,12 @@ HTMLAllCollection
 >
 mAll
 ;
+RefPtr
+<
+ViewTransition
+>
+mActiveViewTransition
+;
 nsTHashSet
 <
 RefPtr