Remove obsolete files from 'sources'. This causes needless work on increment...

base/base.gypi

 # Copyright (c) 2011 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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
     },
     'target_conditions': [
@@ skipping 80 matching lines @@
           'json/json_reader.cc',
           'json/json_reader.h',
           'json/json_writer.cc',
           'json/json_writer.h',
           'json/string_escape.cc',
           'json/string_escape.h',
           'lazy_instance.cc',
           'lazy_instance.h',
           'linked_list.h',
           'linked_ptr.h',
-          'lock.h',
           'logging.cc',
           'logging.h',
           'logging_win.cc',
           'mac/cocoa_protocols.h',
           'mac/mac_util.h',
           'mac/mac_util.mm',
           'mac/os_crash_dumps.cc',
           'mac/os_crash_dumps.h',
           'mac/scoped_aedesc.h',
           'mac/scoped_cftyperef.h',
@@ skipping 615 matching lines @@
             'third_party/xdg_mime/xdgmimemagic.c',
             'third_party/xdg_mime/xdgmimemagic.h',
             'third_party/xdg_mime/xdgmimeparent.c',
             'third_party/xdg_mime/xdgmimeparent.h',
           ],
         },
       ],
     }],
   ],
 }