Make callers of CommandLine use it via the base:: namespace.

chrome/browser/chromeos/login/existing_user_controller_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 <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ skipping 140 matching lines @@
         .WillOnce(Return(mock_login_display_));
     EXPECT_CALL(*mock_login_display_host_.get(), GetNativeWindow())
         .Times(1)
         .WillOnce(ReturnNull());
     EXPECT_CALL(*mock_login_display_host_.get(), OnPreferencesChanged())
         .Times(1);
     EXPECT_CALL(*mock_login_display_, Init(_, false, true, true))
         .Times(1);
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kLoginManager);
   }
 
   virtual void SetUpUserManager() {
     // Replace the UserManager singleton with a mock.
     mock_user_manager_ = new MockUserManager;
     user_manager_enabler_.reset(
         new ScopedUserManagerEnabler(mock_user_manager_));
     EXPECT_CALL(*mock_user_manager_, IsKnownUser(kUsername))
         .Times(AnyNumber())
@@ skipping 575 matching lines @@
   // First run propagates public accounts and stores them in Local State.
 }
 
 // See http://crbug.com/393704; flaky.
 IN_PROC_BROWSER_TEST_F(ExistingUserControllerPublicSessionTest,
                        DISABLED_TestLoadingPublicUsersFromLocalState) {
   // Second run loads list of public accounts from Local State.
 }
 
 }  // namespace chromeos