Added URLLoaderThrottleSafeBrowsingChecks to testing config

Bug: 807399
Change-Id: I7ec3529451a8cd1690a210411ae7120e7223bf9e
Reviewed-on: https://chromium-review.googlesource.com/c/1338234Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Commit-Queue: Carlos IL <carlosil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608797}

testing/variations/fieldtrial_testing_config.json

@@ -4964,6 +4964,25 @@
             ]
         }
     ],
+    "URLLoaderThrottleSafeBrowsingChecks": [
+        {
+            "platforms": [
+                "windows",
+                "mac",
+                "chromeos",
+                "linux",
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "URLLoaderThrottleSafeBrowsingChecksEnabled",
+                    "enable_features": [
+                        "S13nSafeBrowsingCheckByURLLoaderThrottle"
+                    ]
+                }
+            ]
+        }
+    ],
     "UnifiedConsent": [
         {
             "platforms": [