Make iossim binary work on Xcode 5 and 6.

testing/iossim/iossim.gyp

 # 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.
 
 {
   'conditions': [
     ['OS!="ios" or "<(GENERATOR)"=="ninja"', {
       'targets': [
         {
           'target_name': 'iossim',
           'toolsets': ['host'],
           'type': 'executable',
           'variables': {
             'developer_dir': '<!(xcode-select -print-path)',
             # TODO(lliabraa): Once all builders are on Xcode 6 this variable can
             # be removed and the actions gated by this variable can be run by
             # default (crbug.com/385030).
             'xcode_version': '<!(xcodebuild -version | grep Xcode | awk \'{print $2}\')',
           },
           'conditions': [
             ['xcode_version=="6.0"', {
               'variables': {
                 'iphone_sim_path': '<(developer_dir)/../SharedFrameworks',
               },
               'defines': [
                 'IOSSIM_USE_XCODE_6',
               ],
+              'xcode_settings': {
+                # The CoreSimulator.h file generated by class-dump defines a
+                # property of type |NSString*| and a setter for the property
+                # that takes a parameter of type |id|. This type mismatch causes
+                # a compiler warning, so turn off -Werror.
+                'GCC_TREAT_WARNINGS_AS_ERRORS': 'NO',
+              },
               'actions': [
                 {
                   'action_name': 'generate_dvt_foundation_header',
                   'inputs': [
                     '<(iphone_sim_path)/DVTFoundation.framework/Versions/Current/DVTFoundation',
                     '<(PRODUCT_DIR)/class-dump',
                   ],
                   'outputs': [
                     '<(INTERMEDIATE_DIR)/iossim/DVTFoundation.h'
                   ],
@@ skipping 108 matching lines @@
                 'iossim',
               ],
               'message': 'Generating the iossim executable',
             },
           ],
         },
       ],
     }],
   ],
 }