Revert of [BackgroundSync] Trigger Background Sync events when Chrome is backgrounded on Android

content/browser/background_sync/background_sync_manager_unittest.cc

Index: content/browser/background_sync/background_sync_manager_unittest.cc
diff --git a/content/browser/background_sync/background_sync_manager_unittest.cc b/content/browser/background_sync/background_sync_manager_unittest.cc
index 3056594e8845bab0c02f8d65894a56be94ebbf45..22e3c76940c6c2f9b69477cfa681cf276a247ab0 100644
--- a/content/browser/background_sync/background_sync_manager_unittest.cc
+++ b/content/browser/background_sync/background_sync_manager_unittest.cc
@@ -12,7 +12,6 @@
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
-#include "content/browser/background_sync/background_sync_network_observer.h"
 #include "content/browser/background_sync/background_sync_registration_handle.h"
 #include "content/browser/background_sync/background_sync_status.h"
 #include "content/browser/browser_thread_impl.h"
@@ -232,9 +231,6 @@
   }
 
   void SetUp() override {
-    // Don't let the tests be confused by the real-world device connectivity
-    BackgroundSyncNetworkObserver::SetIgnoreNetworkChangeNotifierForTests(true);
-
     helper_.reset(
         new EmbeddedWorkerTestHelper(base::FilePath(), kRenderProcessId));
 
@@ -251,12 +247,6 @@
     // workers.
     base::RunLoop().RunUntilIdle();
     RegisterServiceWorkers();
-  }
-
-  void TearDown() override {
-    // Restore the network observer functionality for subsequent tests
-    BackgroundSyncNetworkObserver::SetIgnoreNetworkChangeNotifierForTests(
-        false);
   }
 
   void RegisterServiceWorkers() {
@@ -312,12 +302,7 @@
   void SetNetwork(net::NetworkChangeNotifier::ConnectionType connection_type) {
     net::NetworkChangeNotifier::NotifyObserversOfNetworkChangeForTests(
         connection_type);
-    if (test_background_sync_manager_) {
-      BackgroundSyncNetworkObserver* network_observer =
-          test_background_sync_manager_->GetNetworkObserverForTesting();
-      network_observer->NotifyManagerIfNetworkChanged(connection_type);
-      base::RunLoop().RunUntilIdle();
-    }
+    base::RunLoop().RunUntilIdle();
   }
 
   void SetOnBatteryPower(bool on_battery_power) {