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

chrome/browser/extensions/api/web_navigation/web_navigation_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 <list>
 #include <set>
 
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 243 matching lines @@
 class WebNavigationApiTest : public ExtensionApiTest {
  public:
   WebNavigationApiTest() {}
   ~WebNavigationApiTest() override {}
 
   void SetUpInProcessBrowserTestFixture() override {
     ExtensionApiTest::SetUpInProcessBrowserTestFixture();
 
     FrameNavigationState::set_allow_extension_scheme(true);
 
-    CommandLine::ForCurrentProcess()->AppendSwitch(
+    base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kAllowLegacyExtensionManifests);
 
     host_resolver()->AddRule("*", "127.0.0.1");
   }
 
   void SetUpOnMainThread() override {
     ExtensionApiTest::SetUpOnMainThread();
     test_navigation_listener_ = new TestNavigationListener();
     resource_dispatcher_host_delegate_.reset(
         new TestResourceDispatcherHostDelegate(
@@ skipping 351 matching lines @@
           "extensions/api_test/webnavigation/crash/b.html",
       embedded_test_server()->port()));
   ui_test_utils::NavigateToURL(browser(), url);
 
   ASSERT_TRUE(catcher.GetNextResult()) << catcher.message();
 }
 
 #endif
 
 }  // namespace extensions