Add numeric_cast for checked integral narrowing casts

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 340 matching lines @@
           'profiler/alternate_timer.h',
           'profiler/tracked_time.cc',
           'profiler/tracked_time.h',
           'rand_util.cc',
           'rand_util.h',
           'rand_util_nacl.cc',
           'rand_util_posix.cc',
           'rand_util_win.cc',
           'run_loop.cc',
           'run_loop.h',
+          'safe_numerics.h',
           'safe_strerror_posix.cc',
           'safe_strerror_posix.h',
           'scoped_native_library.cc',
           'scoped_native_library.h',
           'sequence_checker.h',
           'sequence_checker_impl.cc',
           'sequence_checker_impl.h',
           'sequenced_task_runner.cc',
           'sequenced_task_runner.h',
           'sequenced_task_runner_helpers.h',
@@ skipping 367 matching lines @@
           ['<(use_system_nspr)==1 and >(nacl_untrusted_build)==0', {
             'sources/': [
               ['exclude', '^third_party/nspr/'],
             ],
           }],
         ],
       }],
     ],
   },
 }