Enable extensions by default.

chrome/browser/extensions/extension_browsertest.cc

 // Copyright (c) 2009 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/extensions/extension_browsertest.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_path.h"
@@ skipping 21 matching lines @@
 
 // Base class for extension browser tests. Provides utilities for loading,
 // unloading, and installing extensions.
 void ExtensionBrowserTest::SetUpCommandLine(CommandLine* command_line) {
   // This enables DOM automation for tab contentses.
   EnableDOMAutomation();
 
   // This enables it for extension hosts.
   ExtensionHost::EnableDOMAutomation();
 
-  command_line->AppendSwitch(switches::kEnableExtensions);
-
   PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir_);
   test_data_dir_ = test_data_dir_.AppendASCII("extensions");
 }
 
 bool ExtensionBrowserTest::LoadExtension(const FilePath& path) {
   ExtensionsService* service = browser()->profile()->GetExtensionsService();
   size_t num_before = service->extensions()->size();
   {
     NotificationRegistrar registrar;
     registrar.Add(this, NotificationType::EXTENSION_LOADED,
@@ skipping 131 matching lines @@
     case NotificationType::EXTENSION_HOST_DID_STOP_LOADING:
       std::cout << "Got EXTENSION_HOST_DID_STOP_LOADING notification.\n";
       MessageLoopForUI::current()->Quit();
       break;
 
     default:
       NOTREACHED();
       break;
   }
 }