Enable SequencedWorkerPool to TaskScheduler redirection in testing config.

testing/variations/fieldtrial_testing_config.json

Index: testing/variations/fieldtrial_testing_config.json
diff --git a/testing/variations/fieldtrial_testing_config.json b/testing/variations/fieldtrial_testing_config.json
index fdffeb46d76d73f9ca38823ed61a6252919ab613..7b5a43cba2649e612686f25d43f6103220f869fc 100644
--- a/testing/variations/fieldtrial_testing_config.json
+++ b/testing/variations/fieldtrial_testing_config.json
@@ -194,7 +194,14 @@
             ],
             "experiments": [
                 {
-                    "name": "Default"
+                    "name": "Enabled",
+                    "params": {
+                        "Background": "3;8;0.1;0;30000",
+                        "BackgroundFileIO": "3;8;0.1;0;30000",
+                        "Foreground": "8;32;0.3;0;30000",
+                        "ForegroundFileIO": "8;32;0.3;0;30000",
+                        "RedirectSequencedWorkerPools": "true"
+                    }
                 },
                 {
                     "name": "EnableViaFlag",