[MSE] Prevent false-positive "stalled" event iff MSE used

https://bugs.webkit.org/show_bug.cgi?id=226882
<rdar://problem/79454993>

Reviewed by Alicia Boya Garcia.

Source/WebCore:

"progress" and "stalled" events make no sense in context of MSE:
w3c/media-source#88
and hence they will likely be removed soon:
https://w3c.github.io/media-source/#h-note-19

This patch is authored by Pawel Lampe <pawel.lampe@gmail.com>.
See: #711

* html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::progressEventTimerFired): Only fire the progess event if the player supports progress monitoring.
* platform/graphics/MediaPlayer.cpp:
(WebCore::MediaPlayer::supportsProgressMonitoring const): Forward call to the player private.
* platform/graphics/MediaPlayer.h: Added new supportsProgressMonitoring() method.
* platform/graphics/MediaPlayerPrivate.h:
(WebCore::MediaPlayerPrivateInterface::supportsProgressMonitoring const): Added method, defaulting to true to trigger the old behaviour.
* platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.h: Return false on new supportsProgressMonitoring() method to prevent progress event triggering.

LayoutTests:

* platform/glib/imported/w3c/web-platform-tests/media-source/mediasource-append-buffer-expected.txt: Updated expectations.

Canonical link: https://commits.webkit.org/241359@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@282059 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/html/HTMLMediaElement.cpp

@@ -2885,6 +2885,8 @@ void HTMLMediaElement::progressEventTimerFired()
     ASSERT(m_player);
     if (m_networkState != NETWORK_LOADING)
         return;
+    if (!m_player->supportsProgressMonitoring())
+        return;
 
     MonotonicTime time = MonotonicTime::now();
     Seconds timedelta = time - m_previousProgressTime;

Source/WebCore/platform/graphics/MediaPlayer.cpp

@@ -723,6 +723,11 @@ bool MediaPlayer::supportsScanning() const
     return m_private->supportsScanning();
 }
 
+bool MediaPlayer::supportsProgressMonitoring() const
+{
+    return m_private->supportsProgressMonitoring();
+}
+
 bool MediaPlayer::requiresImmediateCompositing() const
 {
     return m_private->requiresImmediateCompositing();

Source/WebCore/platform/graphics/MediaPlayer.h

@@ -302,6 +302,7 @@ class WEBCORE_EXPORT MediaPlayer : public MediaPlayerEnums, public RefCounted<Me
     bool supportsFullscreen() const;
     bool supportsScanning() const;
     bool canSaveMediaData() const;
+    bool supportsProgressMonitoring() const;
     bool requiresImmediateCompositing() const;
     bool doesHaveAttribute(const AtomString&, AtomString* value = nullptr) const;
     PlatformLayer* platformLayer() const;

Source/WebCore/platform/graphics/MediaPlayerPrivate.h

@@ -84,6 +84,7 @@ class MediaPlayerPrivateInterface {
     virtual bool supportsPictureInPicture() const { return false; }
     virtual bool supportsFullscreen() const { return false; }
     virtual bool supportsScanning() const { return false; }
+    virtual bool supportsProgressMonitoring() const { return true; }
     virtual bool requiresImmediateCompositing() const { return false; }
 
     virtual bool canSaveMediaData() const { return false; }

Source/WebCore/platform/graphics/gstreamer/mse/MediaPlayerPrivateGStreamerMSE.h

@@ -67,6 +67,11 @@ class MediaPlayerPrivateGStreamerMSE : public MediaPlayerPrivateGStreamer {
 
     void sourceSetup(GstElement*) override;
 
+    // return false to avoid false-positive "stalled" event - it should be soon addressed in the spec
+    // see: https://github.com/w3c/media-source/issues/88
+    // see: https://w3c.github.io/media-source/#h-note-19
+    bool supportsProgressMonitoring() const override { return false; }
+
     void setReadyState(MediaPlayer::ReadyState);
     void waitForSeekCompleted();
     void seekCompleted();