Cherry-pick 0ac4c71. rdar://123475213

    Crash in fast/canvas/webgl/tex-image-and-uniform-binding test
    https://bugs.webkit.org/show_bug.cgi?id=268372
    rdar://121921205

    Reviewed by Youenn Fablet.

    It was possible for m_videoLayer to be set to zero before we accessed it in the VideoPlaybackQualityMetrics WorkQueue.

    * Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.h:
    * Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
    (WebCore::MediaPlayerPrivateAVFoundationObjC::createVideoLayer):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::createAVPlayerLayer):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::destroyVideoLayer):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::createAVPlayer):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::platformSetVisible):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::updateVideoLayerGravity):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::videoPlaybackQualityMetrics):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::videoPlaybackQualityMetrics const):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::asyncVideoPlaybackQualityMetrics):
    (WebCore::MediaPlayerPrivateAVFoundationObjC::setShouldDisableHDR):

    Canonical link: https://commits.webkit.org/273785@main

Identifier: 272448.617@safari-7618-branch

Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.h

@@ -368,10 +368,12 @@ class MediaPlayerPrivateAVFoundationObjC final : public MediaPlayerPrivateAVFoun
     bool containsDisabledTracks() const;
     bool trackIsPlayable(AVAssetTrack*) const;
 
+    std::optional<VideoPlaybackQualityMetrics> videoPlaybackQualityMetrics(AVPlayerLayer*) const;
+
     RetainPtr<AVURLAsset> m_avAsset;
     RetainPtr<AVPlayer> m_avPlayer;
     RetainPtr<AVPlayerItem> m_avPlayerItem;
-    RetainPtr<AVPlayerLayer> m_videoLayer;
+    RetainPtr<AVPlayerLayer> m_videoLayer WTF_GUARDED_BY_CAPABILITY(mainThread);
     std::unique_ptr<VideoLayerManagerObjC> m_videoLayerManager;
     MediaPlayer::VideoGravity m_videoFullscreenGravity { MediaPlayer::VideoGravity::ResizeAspect };
     RetainPtr<WebCoreAVFMovieObserver> m_objcObserver;

Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm

@@ -613,6 +613,8 @@ static WallTime toSystemClockTime(NSDate *date)
         return;
 
     ensureOnMainThread([this, weakThis = ThreadSafeWeakPtr { *this }] {
+        assertIsMainThread();
+
         RefPtr protectedThis = weakThis.get();
         if (!protectedThis)
             return;
@@ -631,6 +633,8 @@ static WallTime toSystemClockTime(NSDate *date)
 
 void MediaPlayerPrivateAVFoundationObjC::createAVPlayerLayer()
 {
+    assertIsMainThread();
+
     if (!m_avPlayer)
         return;
 
@@ -659,6 +663,8 @@ static WallTime toSystemClockTime(NSDate *date)
 
 void MediaPlayerPrivateAVFoundationObjC::destroyVideoLayer()
 {
+    assertIsMainThread();
+
     if (!m_videoLayer)
         return;
 
@@ -1082,6 +1088,8 @@ static URL conformFragmentIdentifierForURL(const URL& url)
 
 void MediaPlayerPrivateAVFoundationObjC::createAVPlayer()
 {
+    assertIsMainThread();
+
     if (m_avPlayer)
         return;
 
@@ -1353,6 +1361,8 @@ static URL conformFragmentIdentifierForURL(const URL& url)
 void MediaPlayerPrivateAVFoundationObjC::setVideoFullscreenMode(MediaPlayer::VideoFullscreenMode mode)
 {
 #if PLATFORM(IOS_FAMILY) && !PLATFORM(WATCHOS)
+    assertIsMainThread();
+
     if ([m_videoLayer respondsToSelector:@selector(setPIPModeEnabled:)])
         [m_videoLayer setPIPModeEnabled:(mode & MediaPlayer::VideoFullscreenModePictureInPicture)];
     updateDisableExternalPlayback();
@@ -1411,6 +1421,8 @@ static URL conformFragmentIdentifierForURL(const URL& url)
 
 void MediaPlayerPrivateAVFoundationObjC::platformSetVisible(bool isVisible)
 {
+    assertIsMainThread();
+
     if (!m_videoLayer)
         return;
 
@@ -2215,6 +2227,8 @@ static void fulfillRequestWithKeyData(AVAssetResourceLoadingRequest *request, Ar
 
 void MediaPlayerPrivateAVFoundationObjC::updateVideoLayerGravity(ShouldAnimate shouldAnimate)
 {
+    assertIsMainThread();
+
     if (!m_videoLayer)
         return;
 
@@ -3842,15 +3856,22 @@ void determineChangedTracksFromNewTracksAndOldItems(MediaSelectionGroupAVFObjC*
 
 std::optional<VideoPlaybackQualityMetrics> MediaPlayerPrivateAVFoundationObjC::videoPlaybackQualityMetrics()
 {
-    if (![m_videoLayer respondsToSelector:@selector(videoPerformanceMetrics)])
+    assertIsMainThread();
+
+    return videoPlaybackQualityMetrics(m_videoLayer.get());
+}
+
+std::optional<VideoPlaybackQualityMetrics> MediaPlayerPrivateAVFoundationObjC::videoPlaybackQualityMetrics(AVPlayerLayer* videoLayer) const
+{
+    if (!videoLayer || ![videoLayer respondsToSelector:@selector(videoPerformanceMetrics)])
         return std::nullopt;
 
 #if PLATFORM(WATCHOS)
     return std::nullopt;
 #else
 ALLOW_NEW_API_WITHOUT_GUARDS_BEGIN
 
-    auto metrics = [m_videoLayer videoPerformanceMetrics];
+    auto metrics = [videoLayer videoPerformanceMetrics];
     if (!metrics)
         return std::nullopt;
 
@@ -3872,14 +3893,20 @@ void determineChangedTracksFromNewTracksAndOldItems(MediaSelectionGroupAVFObjC*
 
 auto MediaPlayerPrivateAVFoundationObjC::asyncVideoPlaybackQualityMetrics() -> Ref<VideoPlaybackQualityMetricsPromise>
 {
+    assertIsMainThread();
+
     static std::once_flag onceKey;
     static LazyNeverDestroyed<Ref<WorkQueue>> metricsWorkQueue;
     std::call_once(onceKey, [] {
         metricsWorkQueue.construct(WorkQueue::create("VideoPlaybackQualityMetrics", WorkQueue::QOS::Background));
     });
 
-    return invokeAsync(metricsWorkQueue.get(), [protectedThis = Ref { *this }, this] {
-        return MediaPlayerPrivateInterface::asyncVideoPlaybackQualityMetrics();
+    if (!m_videoLayer)
+        return VideoPlaybackQualityMetricsPromise::createAndReject(PlatformMediaError::NotSupportedError);
+    return invokeAsync(metricsWorkQueue.get(), [protectedThis = Ref { *this }, protectedVideoLayer = m_videoLayer, this] {
+        if (auto metrics = videoPlaybackQualityMetrics(protectedVideoLayer.get()))
+            return VideoPlaybackQualityMetricsPromise::createAndResolve(WTFMove(*metrics));
+        return VideoPlaybackQualityMetricsPromise::createAndReject(PlatformMediaError::NotSupportedError);
     });
 }
 
@@ -3927,6 +3954,8 @@ void determineChangedTracksFromNewTracksAndOldItems(MediaSelectionGroupAVFObjC*
 
 void MediaPlayerPrivateAVFoundationObjC::setShouldDisableHDR(bool shouldDisable)
 {
+    assertIsMainThread();
+
     if (![m_videoLayer respondsToSelector:@selector(setToneMapToStandardDynamicRange:)])
         return;