Address comments on c_frame_pointers CL

tools/gyp/configurations_xcode.gypi

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # The purpose of this file and others in this directory is to simulate
 # the Chromium build enviroment. This file is included in all GYP
 # files that are used by the Dart project.
 
 # READ BEFORE EDITING:
 # Do not add Dart VM specific configuration to this file. Instead,
@@ skipping 47 matching lines @@
           ['c_frame_pointers==1', {
             'xcode_settings': {
               'OTHER_CFLAGS': [
                 '-fno-omit-frame-pointer',
                 '-mno-omit-leaf-frame-pointer',
               ],
             },
             'defines': [
               'PROFILE_NATIVE_CODE',
             ],
-          }, {
-            'xcode_settings': {
-              'OTHER_CFLAGS': [
-                '-fomit-frame-pointer',
-                '-momit-leaf-frame-pointer',
-              ],
-            },
           }],
         ],
       },
       'Dart_Macos_ia32_Base': {
         'abstract': 1,
       },
       'Dart_Macos_x64_Base': {
         'abstract': 1,
       },
       'Dart_Macos_simarm_Base': {
         'abstract': 1,
       },
       'Dart_Macos_simarm64_Base': {
         'abstract': 1,
       },
       'Dart_Macos_simmips_Base': {
         'abstract': 1,
       },
       'Dart_Macos_Debug': {
         'abstract': 1,
       },
       'Dart_Macos_Release': {
         'abstract': 1,
       },
     },
   },
 }