Comment 12 for bug 1672297

Ah yep, that would do it. Just be sure to have the script check the username, because even if you're on a single-user system the gdm user also runs a gnome-shell:

#!/bin/sh
if [ $USER = your_username_here ] ; then exec valgrind --tool=massif --num-callers=32 --log-file=/tmp/gnome-shell.valgrind.log.%p $0.bin $* ; fi
exec $0.bin $*

I ran this and experimented with all the usual applications. Valgrind's RSS was growing slowly as you'd expect until I played a video, then it exploded to > 6 GiB and Wayland hung. I killed Valgrind with -HUP and it did produce a valid profile (attached). Please check if this is what you are after.

I'm now running it again but won't test video playback this time.