[Cocoa] Add nextChildIdentifier() to VideoFullscreenModel

https://bugs.webkit.org/show_bug.cgi?id=257067
rdar://109590097

Reviewed by Eric Carlson.

Multiple WebAVPlayerLayers can exist simultaneously, and disambiguating their logs when they coexist
can be difficult. Use LoggerHelper's concept of a "child identifier", and expose that child
identifier through VideoFullscreenModel. Each WebAVPlayerLayer will get a unique but related
identifier.

* Source/WebCore/platform/cocoa/VideoFullscreenModel.h:
(WebCore::VideoFullscreenModel::nextChildIdentifier const):
* Source/WebCore/platform/cocoa/VideoFullscreenModelVideoElement.h:
* Source/WebCore/platform/cocoa/VideoFullscreenModelVideoElement.mm:
(WebCore::VideoFullscreenModelVideoElement::nextChildIdentifier const):
* Source/WebCore/platform/cocoa/WebAVPlayerLayer.mm:
(-[WebAVPlayerLayer setFullscreenModel:]):
(-[WebAVPlayerLayer videoRect]):
* Source/WebKit/UIProcess/Cocoa/VideoFullscreenManagerProxy.h:
* Source/WebKit/UIProcess/Cocoa/VideoFullscreenManagerProxy.mm:
(WebKit::VideoFullscreenModelContext::nextChildIdentifier const):

Canonical link: https://commits.webkit.org/264309@main

Source/WebCore/platform/cocoa/VideoFullscreenModel.h

@@ -79,6 +79,7 @@ class VideoFullscreenModel : public CanMakeWeakPtr<VideoFullscreenModel> {
 
 #if !RELEASE_LOG_DISABLED
     virtual const void* logIdentifier() const { return nullptr; }
+    virtual const void* nextChildIdentifier() const { return logIdentifier(); }
     virtual const Logger* loggerPtr() const { return nullptr; }
 #endif
 };

Source/WebCore/platform/cocoa/VideoFullscreenModelVideoElement.h

@@ -79,8 +79,9 @@ class VideoFullscreenModelVideoElement : public VideoFullscreenModel, public Eve
     WEBCORE_EXPORT void requestRouteSharingPolicyAndContextUID(CompletionHandler<void(RouteSharingPolicy, String)>&&) override;
 
 #if !RELEASE_LOG_DISABLED
-    const Logger* loggerPtr() const override;
-    WEBCORE_EXPORT const void* logIdentifier() const override;
+    const Logger* loggerPtr() const final;
+    WEBCORE_EXPORT const void* logIdentifier() const final;
+    WEBCORE_EXPORT const void* nextChildIdentifier() const final;
     const char* logClassName() const { return "VideoFullscreenModelVideoElement"; }
     WTFLogChannel& logChannel() const;
 #endif
@@ -112,6 +113,10 @@ class VideoFullscreenModelVideoElement : public VideoFullscreenModel, public Eve
     Vector<RefPtr<TextTrack>> m_legibleTracksForMenu;
     Vector<RefPtr<AudioTrack>> m_audioTracksForMenu;
     std::optional<MediaPlayerIdentifier> m_playerIdentifier;
+
+#if !RELEASE_LOG_DISABLED
+    mutable uint64_t m_childIdentifierSeed { 0 };
+#endif
 };
 
 }

Source/WebCore/platform/cocoa/VideoFullscreenModelVideoElement.mm

@@ -338,6 +338,11 @@
     return m_videoElement ? m_videoElement->logIdentifier() : nullptr;
 }
 
+const void* VideoFullscreenModelVideoElement::nextChildIdentifier() const
+{
+    return LoggerHelper::childLogIdentifier(logIdentifier(), ++m_childIdentifierSeed);
+}
+
 WTFLogChannel& VideoFullscreenModelVideoElement::logChannel() const
 {
     return LogFullscreen;

Source/WebCore/platform/cocoa/WebAVPlayerLayer.mm

@@ -83,6 +83,9 @@ @implementation WebAVPlayerLayer {
     RetainPtr<NSString> _videoGravity;
     RetainPtr<NSString> _previousVideoGravity;
     std::unique_ptr<WebAVPlayerLayerFullscreenModelClient> _fullscreenModelClient;
+#if !RELEASE_LOG_DISABLED
+    const void* _logIdentifier;
+#endif
 }
 
 - (instancetype)init
@@ -127,6 +130,9 @@ - (void)setFullscreenModel:(VideoFullscreenModel*)fullscreenModel
         _fullscreenModel->addClient(*_fullscreenModelClient);
 
     self.videoDimensions = _fullscreenModel->videoDimensions();
+#if !RELEASE_LOG_DISABLED
+    _logIdentifier = _fullscreenModel ? _fullscreenModel->nextChildIdentifier() : nullptr;
+#endif
 }
 
 - (AVPlayerController *)playerController
@@ -358,9 +364,7 @@ + (NSSet *)keyPathsForValuesAffectingVideoRect
 @implementation WebAVPlayerLayer (Logging)
 - (const void*)logIdentifier
 {
-    if (_fullscreenModel)
-        return _fullscreenModel->logIdentifier();
-    return nullptr;
+    return _logIdentifier;
 }
 
 - (const Logger*)loggerPtr

Source/WebKit/UIProcess/Cocoa/VideoFullscreenManagerProxy.h

@@ -133,8 +133,9 @@ class VideoFullscreenModelContext final
     void fullscreenMayReturnToInline() final;
 
 #if !RELEASE_LOG_DISABLED
-    const void* logIdentifier() const override;
-    const Logger* loggerPtr() const override;
+    const void* logIdentifier() const final;
+    const void* nextChildIdentifier() const final;
+    const Logger* loggerPtr() const final;
 
     const char* logClassName() const { return "VideoFullscreenModelContext"; };
     WTFLogChannel& logChannel() const;
@@ -153,6 +154,10 @@ class VideoFullscreenModelContext final
     HashSet<WebCore::VideoFullscreenModelClient*> m_clients;
     WebCore::FloatSize m_videoDimensions;
     bool m_hasVideo { false };
+
+#if !RELEASE_LOG_DISABLED
+    mutable uint64_t m_childIdentifierSeed { 0 };
+#endif
 };
 
 class VideoFullscreenManagerProxy : public RefCounted<VideoFullscreenManagerProxy>, private IPC::MessageReceiver {

Source/WebKit/UIProcess/Cocoa/VideoFullscreenManagerProxy.mm

@@ -381,6 +381,11 @@ - (BOOL)prefersStatusBarHidden
     return m_playbackSessionModel->logIdentifier();
 }
 
+const void* VideoFullscreenModelContext::nextChildIdentifier() const
+{
+    return LoggerHelper::childLogIdentifier(m_playbackSessionModel->logIdentifier(), ++m_childIdentifierSeed);
+}
+
 const Logger* VideoFullscreenModelContext::loggerPtr() const
 {
     return m_playbackSessionModel->loggerPtr();