Modify iOS test_runner to accept 'shards' attribute

Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ie4729da59a1e03797ada6b29c74b95d437837a70
Reviewed-on: https://chromium-review.googlesource.com/898441Reviewed-by: smut <smut@google.com>
Commit-Queue: Menglu Huang <huangml@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533927}

ios/build/bots/scripts/run.py

@@ -48,6 +48,7 @@ def main():
         env_vars=args.env_var,
         mac_toolchain=args.mac_toolchain_cmd,
         retries=args.retries,
+        shards=args.shards,
         test_args=test_args,
         test_cases=args.test_cases,
         xcode_path=args.xcode_path,
@@ -145,6 +146,13 @@ def parse_args():
     metavar='n',
     type=int,
   )
+  parser.add_argument(
+    '-s',
+    '--shards',
+    help='Number of shards to split test cases. (Not implemented yet)',
+    metavar='n',
+    type=int,
+  )
   parser.add_argument(
     '-t',
     '--test-cases',

ios/build/bots/scripts/test_runner.py

@@ -500,6 +500,7 @@ class SimulatorTestRunner(TestRunner):
       env_vars=None,
       mac_toolchain='',
       retries=None,
+      shards=None,
       test_args=None,
       test_cases=None,
       xcode_path='',
@@ -557,6 +558,8 @@ class SimulatorTestRunner(TestRunner):
     self.platform = platform
     self.start_time = None
     self.version = version
+    # TODO(crbug.com/808267): Implement iOS test sharding.
+    self.shards = shards
 
   @staticmethod
   def kill_simulators():