Fix iOS code signing issue

build/config/ios/find_signing_identity.py

 # Copyright (c) 2015 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.
 
 import argparse
 import os
 import subprocess
 import sys
 import re
 
 def ListIdentities():
   return subprocess.check_output([
     'xcrun',
     'security',
     'find-identity',
     '-v',
     '-p',
     'codesigning',
-  ]).strip()
+  ])
 
 
 def FindValidIdentity():
-  lines = ListIdentities().splitlines()
+  lines = list(map(str.strip, ListIdentities().splitlines()))
   # Look for something like "2) XYZ "iPhone Developer: Name (ABC)""
   exp = re.compile('[0-9]+\) ([A-F0-9]+) "([^"]*)"')
   for line in lines:
     res = exp.match(line)
     if res is None:
       continue
     if "iPhone Developer" in res.group(2):
       return res.group(1)
   return ""
 
 
 if __name__ == '__main__':
   parser = argparse.ArgumentParser('codesign iOS bundles')
   parser.add_argument('--developer_dir', required=False,
                       help='Path to Xcode.')
   args = parser.parse_args()
   if args.developer_dir:
     os.environ['DEVELOPER_DIR'] = args.developer_dir
 
   print FindValidIdentity()