pull constant out of trace_event_impl for split_link

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 120 matching lines @@
           'debug/stack_trace.cc',
           'debug/stack_trace.h',
           'debug/stack_trace_android.cc',
           'debug/stack_trace_ios.mm',
           'debug/stack_trace_posix.cc',
           'debug/stack_trace_win.cc',
           'debug/trace_event.h',
           'debug/trace_event_android.cc',
           'debug/trace_event_impl.cc',
           'debug/trace_event_impl.h',
+          'debug/trace_event_impl_constants.cc',
           'debug/trace_event_win.cc',
           'deferred_sequenced_task_runner.cc',
           'deferred_sequenced_task_runner.h',
           'environment.cc',
           'environment.h',
           'file_descriptor_posix.h',
           'file_util.cc',
           'file_util.h',
           'file_util_android.cc',
           'file_util_linux.cc',
@@ skipping 654 matching lines @@
           ['<(use_system_nspr)==1 and >(nacl_untrusted_build)==0', {
             'sources/': [
               ['exclude', '^third_party/nspr/'],
             ],
           }],
         ],
       }],
     ],
   },
 }