Update from https://crrev.com/309717

base/command_line.h

 // 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.
 
 // This class works with command lines: building and parsing.
 // Arguments with prefixes ('--', '-', and on Windows, '/') are switches.
 // Switches will precede all other arguments without switch prefixes.
 // Switches can optionally have values, delimited by '=', e.g., "-switch=value".
 // An argument of "--" will terminate switch parsing during initialization,
 // interpreting subsequent tokens as non-switch arguments, regardless of prefix.
@@ skipping 208 matching lines @@
 
   // Parsed-out switch keys and values.
   SwitchMap switches_;
 
   // The index after the program and switches, any arguments start here.
   size_t begin_args_;
 };
 
 }  // namespace base
 
-// TODO(brettw) remove once all callers specify the namespace properly.
-using base::CommandLine;
-
 #endif  // BASE_COMMAND_LINE_H_