LocalSampleBufferDisplayLayer::enqueueVideoFrame callback needs to ca…

…ll assertIsCurrent after checking weakThis

https://bugs.webkit.org/show_bug.cgi?id=258854
rdar://111744695

Reviewed by Eric Carlson.

Covered by existing tests.

* Source/WebCore/platform/graphics/avfoundation/objc/LocalSampleBufferDisplayLayer.mm:
(WebCore::LocalSampleBufferDisplayLayer::enqueueVideoFrame):

Canonical link: https://commits.webkit.org/265762@main

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

@@ -391,11 +391,11 @@ static inline CGAffineTransform videoTransformationMatrix(VideoFrame& videoFrame
     }
 
     m_processingQueue->dispatch([this, weakThis = ThreadSafeWeakPtr { *this }, pixelBuffer = RetainPtr { videoFrame.pixelBuffer() }, presentationTime = videoFrame.presentationTime(), isReconfiguring]() mutable {
-        assertIsCurrent(workQueue());
-
         auto protectedThis = weakThis.get();
         if (!protectedThis)
             return;
+
+        assertIsCurrent(workQueue());
         if (isReconfiguring)
             m_isReconfiguring = true;