Address more TODO(GYP) in the GN build.

components/crash.gypi

 # Copyright 2013 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.
 
 {
   'targets': [
     {
       # GN version: //components/crash/core/browser
       'target_name': 'crash_core_browser',
       'type': 'static_library',
@@ skipping 416 matching lines @@
                 'Common_Base': {
                   'msvs_target_platform': 'x64',
                 },
               },
             },
           ],
         }],
         ['OS=="mac"', {
           'targets': [
             {
+              # GN version: //components/crash/content/app:breakpad_stubs
               'target_name': 'breakpad_stubs',
               'type': 'static_library',
               'dependencies': [
                 '../base/base.gyp:base',
               ],
               'sources': [
                 'crash/content/app/breakpad_mac.h',
                 'crash/content/app/breakpad_mac_stubs.mm',
                 'crash/content/app/crash_reporter_client.cc',
                 'crash/content/app/crash_reporter_client.h',
@@ skipping 34 matching lines @@
                   ],
                 }],
               ],
             },
           ],
         }],
       ],
     }],
   ],
 }