Revert "[Watch flakes]: Fix flakes from NetworkService."

This reverts commit 0068fa1b.

Reason for revert: CookieManagerImplTest.ReconnectToNetworkContext has been failing flakily: https://ci.chromium.org/p/chromium/builders/ci/Fuchsia%20x64

Original change's description:
> [Watch flakes]: Fix flakes from NetworkService.
> 
> This CL cause NetworkService::CreateForTesting to
> use a mock NetworkChangeNotifier which does not observe network changes
> 
> Bug: 1011275
> Change-Id: I6de34b7a5f6c5af5128cfc000ed63481f3351325
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1864359
> Commit-Queue: Etienne Pierre-Doray <etiennep@chromium.org>
> Reviewed-by: Eric Orth <ericorth@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#709257}

TBR=etiennep@chromium.org,ericorth@chromium.org

Change-Id: I2ae778c2f1d8f28cba45c4e8fd24b1597ea1a504
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1011275
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880246Reviewed-by: Meredith Lane <meredithl@chromium.org>
Commit-Queue: Meredith Lane <meredithl@chromium.org>
Cr-Commit-Position: refs/heads/master@{#709370}

services/network/network_service.cc

@@ -329,12 +329,8 @@ std::unique_ptr<NetworkService> NetworkService::Create(
 }
 
 std::unique_ptr<NetworkService> NetworkService::CreateForTesting() {
-  auto network_service = std::make_unique<NetworkService>(
-      std::make_unique<service_manager::BinderRegistry>(), mojo::NullReceiver(),
-      true /* delay_initialization_until_set_client */);
-  network_service->Initialize(mojom::NetworkServiceParams::New(),
-                              true /* mock_network_change_notifier */);
-  return network_service;
+  return std::make_unique<NetworkService>(
+      std::make_unique<service_manager::BinderRegistry>());
 }
 
 void NetworkService::RegisterNetworkContext(NetworkContext* network_context) {

services/network/network_service.h

@@ -86,9 +86,8 @@ class COMPONENT_EXPORT(NETWORK_SERVICE) NetworkService
   static std::unique_ptr<NetworkService> Create(
       mojo::PendingReceiver<mojom::NetworkService> receiver);
 
-  // Creates a testing instance of NetworkService not bound to an actual Service
-  // pipe. This will cause NetworkChangeNotifier, unless already created, to be
-  // mocked. This instance must be driven by direct calls onto the
+  // Creates a testing instance of NetworkService not bound to an actual
+  // Service pipe. This instance must be driven by direct calls onto the
   // NetworkService object.
   static std::unique_ptr<NetworkService> CreateForTesting();