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

chrome/browser/ui/ash/volume_controller_browsertest_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 <vector>
 
 #include "ash/accessibility_delegate.h"
 #include "ash/ash_switches.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 221 matching lines @@
   VolumeUp();
   ASSERT_FALSE(audio_handler_->IsOutputMuted());
   EXPECT_EQ(4, num_play_requests());
 }
 
 class VolumeControllerSoundsDisabledTest : public VolumeControllerSoundsTest {
  public:
   VolumeControllerSoundsDisabledTest() {}
   virtual ~VolumeControllerSoundsDisabledTest() {}
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     VolumeControllerSoundsTest::SetUpCommandLine(command_line);
     command_line->AppendSwitch(chromeos::switches::kDisableVolumeAdjustSound);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(VolumeControllerSoundsDisabledTest);
 };
 
 IN_PROC_BROWSER_TEST_F(VolumeControllerSoundsDisabledTest,
                        VolumeAdjustSounds) {
   EXPECT_FALSE(is_sound_initialized());
 
   // Check that sound isn't played on volume up and volume down.
   audio_handler_->SetOutputVolumePercent(50);
   VolumeUp();
   VolumeDown();
   EXPECT_EQ(0, num_play_requests());
 }
 
 }  // namespace