[WebGPU] MTLCaptureManager stops capturing frame too soon

https://bugs.webkit.org/show_bug.cgi?id=262940>
<radar://116716543>

Reviewed by Dan Glastonbury.

We want to end capture after queue calls submit as there may
be multiple command buffers.

* Source/WebGPU/WebGPU/Queue.mm:
(WebGPU::Queue::commitMTLCommandBuffer):
(WebGPU::Queue::submit):

Canonical link: https://commits.webkit.org/269132@main

Source/WebGPU/WebGPU/Queue.mm

@@ -157,9 +157,6 @@
 
     [commandBuffer commit];
     ++m_submittedCommandBufferCount;
-
-    if ([MTLCaptureManager sharedCaptureManager].isCapturing)
-        [[MTLCaptureManager sharedCaptureManager] stopCapture];
 }
 
 void Queue::submit(Vector<std::reference_wrapper<const CommandBuffer>>&& commands)
@@ -175,6 +172,9 @@
 
     for (auto commandBuffer : commands)
         commitMTLCommandBuffer(commandBuffer.get().commandBuffer());
+
+    if ([MTLCaptureManager sharedCaptureManager].isCapturing)
+        [[MTLCaptureManager sharedCaptureManager] stopCapture];
 }
 
 static bool validateWriteBufferInitial(size_t size)