[ios] Add support for filtering codesiging identity.

build/config/ios/find_signing_identity.py

Index: build/config/ios/find_signing_identity.py
diff --git a/build/config/ios/find_signing_identity.py b/build/config/ios/find_signing_identity.py
index 736e2e4b5c919d96267da27a7ddb3aec4d0b7341..7add474b9c3723a05830d27efb9da3c62cee895a 100644
--- a/build/config/ios/find_signing_identity.py
+++ b/build/config/ios/find_signing_identity.py
@@ -19,7 +19,7 @@ def ListIdentities():
   ])
 
 
-def FindValidIdentity():
+def FindValidIdentity(identity_description):
   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]+) "([^"]*)"')
@@ -27,17 +27,21 @@ def FindValidIdentity():
     res = exp.match(line)
     if res is None:
       continue
-    if "iPhone Developer" in res.group(2):
-      return res.group(1)
-  return ""
+    if identity_description in res.group(2):
+      yield res.group(1)
 
 
 if __name__ == '__main__':
   parser = argparse.ArgumentParser('codesign iOS bundles')
-  parser.add_argument('--developer_dir', required=False,
-                      help='Path to Xcode.')
+  parser.add_argument(
+      '--developer_dir', required=False,
+      help='Path to Xcode.')
+  parser.add_argument(
+      '--identity-description', required=True,
+      help='Text description used to select the code signing identity.')
   args = parser.parse_args()
   if args.developer_dir:
     os.environ['DEVELOPER_DIR'] = args.developer_dir
 
-  print FindValidIdentity()
+  for identity in FindValidIdentity(args.identity_description):
+    print identity