Reland 54771 (and 54795) To enable TCP Preconnection by default...

chrome/browser/browser_main.cc

 // Copyright (c) 2010 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 "chrome/browser/browser_main.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 1187 matching lines @@
 
   // Sets things up so that if we crash from this point on, a dialog will
   // popup asking the user to restart chrome. It is done this late to avoid
   // testing against a bunch of special cases that are taken care early on.
   PrepareRestartOnCrashEnviroment(parsed_command_line);
 
   // Initialize and maintain network predictor module, which handles DNS
   // pre-resolution, as well as TCP/IP connection pre-warming.
   // This also registers an observer to discard data when closing incognito
   // mode.
+  bool preconnect_enabled = true;  // Default status (easy to change!).
+  if (parsed_command_line.HasSwitch(switches::kDisablePreconnect))
+    preconnect_enabled = false;
+  else if (parsed_command_line.HasSwitch(switches::kEnablePreconnect))
+    preconnect_enabled = true;
   chrome_browser_net::PredictorInit dns_prefetch(
       user_prefs,
       local_state,
-      parsed_command_line.HasSwitch(switches::kEnablePreconnect),
+      preconnect_enabled,
       parsed_command_line.HasSwitch(switches::kPreconnectDespiteProxy));
 
 #if defined(OS_WIN)
   win_util::ScopedCOMInitializer com_initializer;
 
   // Init the RLZ library. This just binds the dll and schedules a task on the
   // file thread to be run sometime later. If this is the first run we record
   // the installation event.
   RLZTracker::InitRlzDelayed(is_first_run, master_prefs.ping_delay);
 #endif
@@ skipping 176 matching lines @@
 
   metrics->Stop();
 
   // browser_shutdown takes care of deleting browser_process, so we need to
   // release it.
   ignore_result(browser_process.release());
   browser_shutdown::Shutdown();
 
   return result_code;
 }