Add -Wno-deprecated-declarations on iOS in preparation of changing SDK.

ios/chrome/ios_chrome.gyp

 # Copyright 2014 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 642 matching lines @@
             'browser/safe_browsing/safe_browsing_service.cc',
             'browser/safe_browsing/safe_browsing_service.h',
             'browser/safe_browsing/ui_manager.cc',
             'browser/safe_browsing/ui_manager.h',
           ],
           'dependencies': [
             'ios_chrome_safe_browsing_proto',
           ],
         }]
       ],
+      # TODO(crbug.com/569158): Suppresses warnings that are treated as errors
+      # when minimum iOS version support is increased to iOS 9 and up.
+      # This should be removed once all deprecation violations have been fixed.
+      'xcode_settings': {
+        'WARNING_CFLAGS': [
+          '-Wno-deprecated-declarations',
+        ],
+      },
     },
     {
       # GN version: //ios/chrome/browser:about_flags
       # This is a separate target so that the 'defines' does not leak to the
       # other files (which would increase the compilation time when changing
       # the value).
       'target_name': 'ios_chrome_browser_about_flags',
       'type': 'static_library',
       'include_dirs': [
         '../..',
@@ skipping 162 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/safe_browsing',
             'proto_out_dir': 'ios/chrome/browser/safe_browsing',
           },
           'includes': [ '../../build/protoc.gypi' ],
         },
       ],
     }],
   ],
 }