Unreview unified build fix for MediaPlayerPrivateWirelessPlayback.cpp.

https://bugs.webkit.org/show_bug.cgi?id=313599
rdar://175804637

Reviewed by Mike Wyrzykowski.

* Source/WebCore/platform/graphics/MediaPlayerPrivateWirelessPlayback.cpp:

Canonical link: https://commits.webkit.org/312252@main

Author: megangardner

Source/WebCore/platform/graphics/MediaPlayerPrivateWirelessPlayback.cpp

@@ -34,6 +34,7 @@
 #include <pal/avfoundation/MediaTimeAVFoundation.h>
 #include <wtf/BlockPtr.h>
 #include <wtf/TZoneMallocInlines.h>
+#include <wtf/darwin/DispatchExtras.h>
 
 #include <pal/cf/CoreMediaSoftLink.h>