Enable SequencedWorkerPool to TaskScheduler redirection in testing config.

testing/variations/fieldtrial_testing_config.json

 {
     "AndroidSessionNotifications": [
         {
             "platforms": [
                 "android"
             ],
             "experiments": [
                 {
                     "name": "Disabled"
                 }
@@ skipping 188 matching lines @@
                 {
                     "name": "EnableViaFlag",
                     "forcing_flag": "enable-browser-task-scheduler",
                     "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": "Enabled",

[gab, 2016/10/24 19:51:29]

I think the first group is the one that runs by default (i.e. you need to
replace "Default" above with this)

[fdoray, 2016/10/25 13:06:53]

Done.

+                    "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"
+                    }
                 }
             ]
         }
     ],
     "CaptivePortalInterstitial": [
         {
             "platforms": [
                 "chromeos",
                 "linux",
                 "mac",
@@ skipping 2035 matching lines @@
                 {
                     "name": "Enabled",
                     "enable_features": [
                         "use-new-media-cache"
                     ]
                 }
             ]
         }
     ]
 }