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

chrome/browser/extensions/api/file_system/file_system_apitest.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 "apps/saved_files_service.h"
 #include "base/files/file_util.h"
 #include "base/path_service.h"
 #include "base/scoped_observer.h"
 #include "build/build_config.h"
 #include "chrome/browser/apps/app_browsertest_util.h"
@@ skipping 46 matching lines @@
   service->RegisterFileEntry(
       extension->id(), "magic id", path_to_save, is_directory);
 }
 
 const int kGraylistedPath = base::DIR_HOME;
 
 }  // namespace
 
 class FileSystemApiTest : public PlatformAppBrowserTest {
  public:
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     PlatformAppBrowserTest::SetUpCommandLine(command_line);
     test_root_folder_ = test_data_dir_.AppendASCII("api_test")
         .AppendASCII("file_system");
     FileSystemChooseEntryFunction::RegisterTempExternalFileSystemForTest(
         "test_root", test_root_folder_);
   }
 
   void SetUpOnMainThread() override { ClearCommandLineArgs(); }
 
   void TearDown() override {
@@ skipping 548 matching lines @@
   AppLoadObserver observer(profile(),
                            base::Bind(AddSavedEntry,
                                       test_directory,
                                       true,
                                       apps::SavedFilesService::Get(profile())));
   ASSERT_TRUE(RunPlatformAppTest("api_test/file_system/restore_directory"))
       << message_;
 }
 
 }  // namespace extensions