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

chrome/browser/chromeos/login/lock/screen_locker_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 "chrome/browser/chromeos/login/lock/screen_locker.h"
 
 #include "ash/wm/window_state.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 111 matching lines @@
   virtual void SetUpInProcessBrowserTestFixture() override {
     fake_session_manager_client_ = new FakeSessionManagerClient;
     DBusThreadManager::GetSetterForTesting()->SetSessionManagerClient(
         scoped_ptr<SessionManagerClient>(fake_session_manager_client_));
 
     InProcessBrowserTest::SetUpInProcessBrowserTestFixture();
     zero_duration_mode_.reset(new ui::ScopedAnimationDurationScaleMode(
         ui::ScopedAnimationDurationScaleMode::ZERO_DURATION));
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitchASCII(switches::kLoginProfile, "user");
   }
 
   scoped_ptr<ui::ScopedAnimationDurationScaleMode> zero_duration_mode_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenLockerTest);
 };
 
 IN_PROC_BROWSER_TEST_F(ScreenLockerTest, TestBasic) {
   ScreenLocker::Show();
@@ skipping 152 matching lines @@
   EXPECT_EQ("", tester->GetPassword());
 
   // Close the locker to match expectations.
   ScreenLocker::Hide();
   content::RunAllPendingInMessageLoop();
   EXPECT_FALSE(tester->IsLocked());
   EXPECT_TRUE(VerifyLockScreenDismissed());
 }
 
 }  // namespace chromeos