spec: Jenkins chrome performance build use PATCHSET_TAG
spec: Jenkins chrome performance build use PATCHSET_TAG

currently the chrome performance build jenkinsfile is hardcoded
to use master. This change will now have it use the jenkins
parameter PATCHSET_TAG.

flag = none

Change-Id: I221501cc8743850c79a89666bd4fa8da0de54fcc
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/240447
Tested-by: Service Cloud Jenkins <9144042a601061f88f1e1d7a1753ea3e2972119d@instructure.com>
Reviewed-by: Rex Fleischer <360d56e185853f069087eaa5288d1374fc56d750@instructure.com>
QA-Review: James Butters <4c5a489c9bb72d41f20b3b22aaf4c9b864e32f20@instructure.com>
Product-Review: James Butters <4c5a489c9bb72d41f20b3b22aaf4c9b864e32f20@instructure.com>

sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,sfu/canvas-lms