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

chrome/browser/chromeos/system/tray_accessibility_browsertest.cc

Index: chrome/browser/chromeos/system/tray_accessibility_browsertest.cc
diff --git a/chrome/browser/chromeos/system/tray_accessibility_browsertest.cc b/chrome/browser/chromeos/system/tray_accessibility_browsertest.cc
index c9333370c497c397804c77d7d908c97eaac13854..3323842945c7bde9b7f220015514db07340d8538 100644
--- a/chrome/browser/chromeos/system/tray_accessibility_browsertest.cc
+++ b/chrome/browser/chromeos/system/tray_accessibility_browsertest.cc
@@ -75,7 +75,7 @@ class TrayAccessibilityTest
     AccessibilityManager::SetBrailleControllerForTest(&braille_controller_);
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  virtual void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kLoginManager);
     command_line->AppendSwitchASCII(switches::kLoginProfile,
                                     TestingProfile::kTestUserProfileDir);