PM: Make WorkerWatcherTest pass in both feature default states.

Bug: 1143281
Change-Id: Id8e82c2af615611207a73cede662cf24e39f6599
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2571959
Commit-Queue: Sigurður Ásgeirsson <siggi@chromium.org>
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Auto-Submit: Sigurður Ásgeirsson <siggi@chromium.org>
Reviewed-by: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833377}

components/performance_manager/worker_watcher_unittest.cc

@@ -1336,7 +1336,8 @@ void WorkerWatcherTest::TestFrameDestroyed(
     feature_list.InitAndEnableFeature(
         features::kServiceWorkerRelationshipsInGraph);
   } else {
-    feature_list.Init();
+    feature_list.InitAndDisableFeature(
+        features::kServiceWorkerRelationshipsInGraph);
   }
 
   int render_process_id = process_node_source()->CreateProcessNode();