Config feature FilterAdsOnAbusiveSites in fieldtrial_testing_config.json

Bug: 891888
Change-Id: I2922c7b24cf688387af8c15d58523fd0f45b1f7a
Reviewed-on: https://chromium-review.googlesource.com/c/1259546Reviewed-by: Steven Holte <holte@chromium.org>
Commit-Queue: Yao Xiao <yaoxia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598922}

testing/variations/fieldtrial_testing_config.json

@@ -1882,6 +1882,25 @@
             ]
         }
     ],
+    "FilterAdsOnAbusiveSites": [
+        {
+            "platforms": [
+                "android",
+                "chromeos",
+                "linux",
+                "mac",
+                "windows"
+            ],
+            "experiments": [
+                {
+                    "name": "Enabled",
+                    "enable_features": [
+                        "FilterAdsOnAbusiveSites"
+                    ]
+                }
+            ]
+        }
+    ],
     "FrameTypePriorityExperiment": [
         {
             "platforms": [