base: Change WeakPtr to use SequenceChecker instead of ThreadChecker.

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.
 
 {
   'target_defaults': {
     'variables': {
       'base_target': 0,
     },
     'target_conditions': [
@@ skipping 681 matching lines @@
                'path_service.cc',
                'platform_file_posix.cc',
                'posix/unix_domain_socket_linux.cc',
                'process_posix.cc',
                'process_util.cc',
                'process_util_posix.cc',
                'rand_util_posix.cc',
                'scoped_native_library.cc',
                'files/scoped_temp_dir.cc',
                'sys_info_posix.cc',
-               'threading/sequenced_worker_pool.cc',
                'third_party/dynamic_annotations/dynamic_annotations.c',
             ],
             'sources/': [
               # Metrics won't work in the NaCl sandbox.
               ['exclude', '^metrics/'],
               ['include', '^threading/platform_thread_linux\\.cc$'],
             ],
           }],
           ['OS == "android" and >(nacl_untrusted_build)==0', {
             'sources!': [
@@ skipping 150 matching lines @@
           ['<(use_system_nspr)==1 and >(nacl_untrusted_build)==0', {
             'sources/': [
               ['exclude', '^third_party/nspr/'],
             ],
           }],
         ],
       }],
     ],
   },
 }