Disable -Wshorten-64-to-32 when building with Xcode for arm64

build/common.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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 4328 matching lines @@
               'OTHER_CFLAGS': [
                 '-Xclang', '-add-plugin', '-Xclang', '<(clang_add_plugin)',
               ],
             }],
             ['clang==1 and "<(GENERATOR)"=="ninja"', {
               'OTHER_CFLAGS': [
                 # See http://crbug.com/110262
                 '-fcolor-diagnostics',
               ],
             }],
+            ['OS=="ios" and target_subarch!="arm32" and \
+              "<(GENERATOR)"=="ninja"', {
+              'OTHER_CFLAGS': [
+                # TODO(ios): when building Chrome for iOS on 64-bit platform
+                # with Xcode, the -Wshorted-64-to-32 warning is automatically
+                # enabled. This cause failures when compiling protobuf code,
+                # so disable the warning. http://crbug.com/359107
+                '-Wno-shorten-64-to-32',
+              ],
+            }],
           ],
         },
         'conditions': [
           ['clang==1', {
             'variables': {
               'clang_dir': '../third_party/llvm-build/Release+Asserts/bin',
             },
           }],
           ['asan==1', {
             'xcode_settings': {
@@ skipping 847 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }