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

content/app/content_main_runner.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/public/app/content_main_runner.h"
 
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ skipping 646 matching lines @@
   }
 
   int Run() override {
     DCHECK(is_initialized_);
     DCHECK(!is_shutdown_);
     const base::CommandLine& command_line =
         *base::CommandLine::ForCurrentProcess();
     std::string process_type =
         command_line.GetSwitchValueASCII(switches::kProcessType);
 
-    // --enable-network-service requires both --enable-browser-side-navigation
-    // (PlzNavigate) and the LoadingWithMojo feature.
-    if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kEnableNetworkService)) {
-      base::CommandLine::ForCurrentProcess()->AppendSwitch(
-          switches::kEnableBrowserSideNavigation);
-      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
-          switches::kEnableFeatures, features::kLoadingWithMojo.name);
-    }
-
     // Run this logic on all child processes. Zygotes will run this at a later
     // point in time when the command line has been updated.
     std::unique_ptr<base::FieldTrialList> field_trial_list;
     if (!process_type.empty() && process_type != switches::kZygoteProcess)
       InitializeFieldTrialAndFeatureList(&field_trial_list);
 
     base::HistogramBase::EnableActivityReportHistogram(process_type);
 
     MainFunctionParams main_params(command_line);
     main_params.ui_task = ui_task_;
@@ skipping 65 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ContentMainRunnerImpl);
 };
 
 // static
 ContentMainRunner* ContentMainRunner::Create() {
   return new ContentMainRunnerImpl();
 }
 
 }  // namespace content