Bug 1712329: Enable mochitest-media tests for msix variant r=jmaher,ahal

This test suite seems to be green on try already.

Differential Revision: https://phabricator.services.mozilla.com/D164084

taskcluster/ci/config.yml

@@ -84,6 +84,7 @@ treeherder:
         'M-wmfme': 'Mochitests with Windows Media Foundation media engine enabled'
         'M-f': 'Mochitest failures'
         'M-dt-no-eft-nofis': 'DevTools Mochitests with EFT without fission enabled'
+        'M-msix': 'Mochitests from MSIX builds'
         'MSI': 'Repack installers into MSIs'
         'MSIs': 'Signing of Repacked installers of MSIs'
         'MSIX': 'Repack into MSIX package'

taskcluster/ci/test/mochitest.yml

@@ -9,6 +9,10 @@ job-defaults:
         by-test-platform:
             android-em-7.*: geckoview-test_runner.apk
             android-hw.*: geckoview-test_runner.apk
+            windows10-64-2004-shippable-qr/opt:
+                by-variant:
+                    msix: target.installer.msix
+                    default: null
             default: null
     tier:
         by-variant:
@@ -41,6 +45,13 @@ job-defaults:
                     - unittests/mac_unittest.py
                 windows.*:
                     - unittests/win_unittest.py
+        requires-signed-builds:
+            by-test-platform:
+                windows10-64-2004-shippable-qr/opt:
+                    by-variant:
+                        msix: true
+                        default: false
+                default: false
 
 mochitest-plain:
     description: "Mochitest plain run"
@@ -534,6 +545,7 @@ mochitest-media:
         - webrender-sw+no-fission
         - webrender-sw
         - wmf-media-engine
+        - msix
     run-on-projects:
         by-variant:
             webgl-ipc:
@@ -588,6 +600,10 @@ mochitest-media:
                 by-test-platform:
                     windows10-64-2004.*: ['autoland', 'mozilla-central']
                     default: []
+            msix:
+                by-test-platform:
+                    windows10-64-2004-shippable-qr/opt: built-projects
+                    default: []
             default:
                 by-test-platform:
                     android.*: []

taskcluster/ci/test/variants.yml

@@ -302,3 +302,13 @@ a11y-no-cache:
         mozharness:
             extra-options:
                 - "--setpref=accessibility.cache.enabled=false"
+
+msix:
+    description: "{description} from msix packages"
+    component: "Firefox:Installer"
+    expiration: "never"
+    suffix: "msix"
+    merge:
+        mozharness:
+            extra-options:
+                - "--installer-path installer.msix"