Enable captive portal detection by default.

chrome/browser/captive_portal/captive_portal_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 <map>
 #include <set>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 895 matching lines @@
                             GURL(kMockCaptivePortalTestUrl));
 }
 
 void CaptivePortalBrowserTest::CleanUpOnMainThread() {
   // No test should have a captive portal check pending on quit.
   EXPECT_FALSE(CheckPending(browser()));
 }
 
 void CaptivePortalBrowserTest::SetUpCommandLine(
     CommandLine* command_line) {
-  command_line->AppendSwitch(switches::kCaptivePortalDetection);
+  command_line->AppendSwitchASCII(switches::kCaptivePortalDetection,
+                                  switches::kCaptivePortalDetectionEnabled);
 }
 
 void CaptivePortalBrowserTest::EnableCaptivePortalDetection(
     Profile* profile, bool enabled) {
   profile->GetPrefs()->SetBoolean(prefs::kAlternateErrorPagesEnabled, enabled);
 }
 
 void CaptivePortalBrowserTest::SetUpCaptivePortalService(Profile* profile,
                                                          const GURL& test_url) {
   CaptivePortalService* captive_portal_service =
@@ skipping 1070 matching lines @@
       base::Bind(&AddHstsHost,
                  make_scoped_refptr(browser()->profile()->GetRequestContext()),
                  http_timeout_url.host()));
 
   SlowLoadBehindCaptivePortal(browser(), true, http_timeout_url);
   Login(browser(), 1, 0);
   FailLoadsAfterLogin(browser(), 1);
 }
 
 }  // namespace captive_portal