Move MatchPattern to its own header and the base namespace.

base/base.gypi

 # 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.
 
 {
   'includes': [
     'trace_event/trace_event.gypi',
   ],
   'target_defaults': {
     'variables': {
@@ skipping 524 matching lines @@
           'sequenced_task_runner_helpers.h',
           'sha1.h',
           'sha1_portable.cc',
           'sha1_win.cc',
           'single_thread_task_runner.h',
           'stl_util.h',
           'strings/latin1_string_conversions.cc',
           'strings/latin1_string_conversions.h',
           'strings/nullable_string16.cc',
           'strings/nullable_string16.h',
+          'strings/pattern.cc',
+          'strings/pattern.h',
           'strings/safe_sprintf.cc',
           'strings/safe_sprintf.h',
           'strings/string16.cc',
           'strings/string16.h',
           'strings/string_number_conversions.cc',
           'strings/string_number_conversions.h',
           'strings/string_piece.cc',
           'strings/string_piece.h',
           'strings/string_split.cc',
           'strings/string_split.h',
@@ skipping 474 matching lines @@
           'i18n/time_formatting.h',
           'i18n/timezone.cc',
           'i18n/timezone.h',
           'i18n/utf8_validator_tables.cc',
           'i18n/utf8_validator_tables.h',
         ],
       }]
     ],
   },
 }