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

chrome/browser/prefetch/prefetch_browsertest.cc

 // Copyright 2013 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 "base/command_line.h"
 #include "base/prefs/pref_service.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 31 matching lines @@
   ConnectionType GetCurrentConnectionType() const override {
     return NetworkChangeNotifier::CONNECTION_4G;
   }
 };
 
 class PrefetchBrowserTestBase : public InProcessBrowserTest {
  public:
   explicit PrefetchBrowserTestBase(bool disabled_via_field_trial)
       : disabled_via_field_trial_(disabled_via_field_trial) {}
 
-  void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(base::CommandLine* command_line) override {
     if (disabled_via_field_trial_) {
       command_line->AppendSwitchASCII(switches::kForceFieldTrials,
                                       "Prefetch/ExperimentDisabled/");
     }
   }
 
   void SetPreference(NetworkPredictionOptions value) {
     browser()->profile()->GetPrefs()->SetInteger(
         prefs::kNetworkPredictionOptions, value);
   }
@@ skipping 147 matching lines @@
                                      kHangingUrl,
                                      loop_.QuitClosure()));
   ui_test_utils::NavigateToURL(browser(), GURL("about:blank"));
   content::RenderFrameHost* rfh =
       browser()->tab_strip_model()->GetActiveWebContents()->GetMainFrame();
   rfh->Send(new PrefetchMsg_Prefetch(rfh->GetRoutingID(), kHangingUrl));
   loop_.Run();
 }
 
 }  // namespace