Revert of Add BrowserScheduler field trial to testing config for desktop.

testing/variations/fieldtrial_testing_config.json

 {
     "AndroidSessionNotifications": [
         {
             "platforms": [
                 "android"
             ],
             "experiments": [
                 {
                     "name": "Disabled"
                 }
@@ skipping 163 matching lines @@
         {
             "platforms": [
                 "win"
             ],
             "experiments": [
                 {
                     "name": "Enabled"
                 }
             ]
         }
-    ],
-    "BrowserScheduler": [
-        {
-            "platforms": [
-                "chromeos",
-                "linux",
-                "mac",
-                "win"
-            ],
-            "experiments": [
-                {
-                    "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"
-                    }
-                }
-            ]
-        }
     ],
     "CaptivePortalInterstitial": [
         {
             "platforms": [
                 "chromeos",
                 "linux",
                 "mac",
                 "win"
             ],
             "experiments": [
@@ skipping 1994 matching lines @@
                 {
                     "name": "Enabled",
                     "enable_features": [
                         "use-new-media-cache"
                     ]
                 }
             ]
         }
     ]
 }