Add a feature flag for network service and about:flags entry for it.

content/browser/site_per_process_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/site_per_process_browsertest.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 46 matching lines @@
 #include "content/common/view_messages.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/interstitial_page_delegate.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "content/public/common/browser_side_navigation_policy.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/content_browser_test_utils.h"
 #include "content/public/test/navigation_handle_observer.h"
 #include "content/public/test/test_frame_navigation_observer.h"
 #include "content/public/test/test_navigation_observer.h"
 #include "content/public/test/test_utils.h"
 #include "content/shell/browser/shell.h"
 #include "content/test/content_browser_test_utils_internal.h"
@@ skipping 2416 matching lines @@
   EXPECT_TRUE(NavigateToURL(shell(), main_url));
 
   // It is safe to obtain the root frame tree node here, as it doesn't change.
   FrameTreeNode* root = web_contents()->GetFrameTree()->root();
   FrameTreeNode* child = root->child_at(0);
   GURL url_a = child->current_url();
 
   // Disable host resolution in the test server and try to navigate the subframe
   // cross-site, which will lead to a committed net error.
   GURL url_b = embedded_test_server()->GetURL("b.com", "/title3.html");
-  bool network_service = base::CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableNetworkService);
+  bool network_service =
+      base::FeatureList::IsEnabled(features::kNetworkService);
   mojom::URLLoaderFactoryPtr failing_factory;
   mojo::MakeStrongBinding(base::MakeUnique<FailingLoadFactory>(),
                           mojo::MakeRequest(&failing_factory));
   StoragePartitionImpl* storage_partition = nullptr;
   if (network_service) {
     storage_partition = static_cast<StoragePartitionImpl*>(
         BrowserContext::GetDefaultStoragePartition(
             shell()->web_contents()->GetBrowserContext()));
     storage_partition->url_loader_factory_getter()->SetNetworkFactoryForTesting(
         std::move(failing_factory));
@@ skipping 7964 matching lines @@
 
   // The new tab's grandchild frame should reuse the b.com process.
   EXPECT_EQ(root->child_at(0)->current_frame_host()->GetProcess(),
             new_shell_root->child_at(0)
                 ->child_at(0)
                 ->current_frame_host()
                 ->GetProcess());
 }
 
 }  // namespace content