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

chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager_policy_browsertest.cc

 // Copyright 2014 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 "ash/desktop_background/desktop_background_controller.h"
 #include "ash/desktop_background/desktop_background_controller_observer.h"
 #include "ash/shell.h"
@@ skipping 153 matching lines @@
 
   // LoginManagerTest:
   virtual void SetUpInProcessBrowserTestFixture() override {
     DBusThreadManager::GetSetterForTesting()->SetSessionManagerClient(
         scoped_ptr<SessionManagerClient>(fake_session_manager_client_));
 
     LoginManagerTest::SetUpInProcessBrowserTestFixture();
     ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir_));
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     // Set the same switches as LoginManagerTest, except that kMultiProfiles is
     // only set when GetParam() is true and except that kLoginProfile is set
     // when GetParam() is false.  The latter seems to be required for the sane
     // start-up of user profiles.
     command_line->AppendSwitch(switches::kLoginManager);
     command_line->AppendSwitch(switches::kForceLoginManagerInTests);
   }
 
   virtual void SetUpOnMainThread() override {
     LoginManagerTest::SetUpOnMainThread();
@@ skipping 211 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(WallpaperManagerPolicyTest, PersistOverLogout) {
   LoginUser(kTestUsers[0]);
 
   // Wait until wallpaper has been loaded.
   RunUntilWallpaperChangeCount(1);
   ASSERT_EQ(kRedImageColor, GetAverageBackgroundColor());
 }
 
 }  // namespace chromeos