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

chrome/browser/chromeos/extensions/input_method_apitest_chromeos.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 "chrome/browser/extensions/extension_apitest.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
@@ skipping 46 matching lines @@
       manager->GetActiveIMEState()->EnableLoginLayouts(kLoginScreenUILanguage,
                                                        keyboard_layouts);
     }
   }
 
  private:
   content::NotificationRegistrar registrar_;
 };
 
 class ExtensionInputMethodApiTest : public ExtensionApiTest {
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         "ilanclmaeigfpnmdlgelmhkpkegdioip");
   }
 };
 
 }  // namespace
 
 IN_PROC_BROWSER_TEST_F(ExtensionInputMethodApiTest, Basic) {
   // Listener for extension's background ready.
   TestListener listener;
 
   ASSERT_TRUE(RunExtensionTest("input_method")) << message_;
 }