Backed out changeset b48c85131790 (bug 1715760) for multiple reftest failures

taskcluster/ci/test/reftest.yml

@@ -264,14 +264,14 @@ reftest-snapshot:
     virtualization: virtual
     variants:
         by-test-platform:
-            linux1804-64-qr/debug: ['fission', 'webrender-sw']
-            linux1804-64-asan-qr/opt: ['fission', 'webrender-sw']
+            linux1804-64-qr/debug: ['webrender-sw']
+            linux1804-64-asan-qr/opt: ['webrender-sw']
             default: []
     run-on-projects:
         by-variant:
             fission:
                 by-test-platform:
-                    linux1804-64-qr/debug: ['trunk']
+                    linux1804-64/debug: ['trunk']
                     default: []
             default: []
     chunks: 8