Implement generate_test_repeat_args for Telemetry unittest script

Bug: 893618
Change-Id: Idbfa57949f173847d2985e528fe05bdf1a2e93a2
Reviewed-on: https://chromium-review.googlesource.com/c/1287033
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600634}

testing/scripts/common.py

@@ -228,7 +228,7 @@ class BaseIsolatedScriptArgsAdapter(object):
         '--isolated-script-test-filter', type=str,
         required=False)
     self._parser.add_argument(
-        '--isolated-script-test-repeat', type=str,
+        '--isolated-script-test-repeat', type=int,
         required=False)
     self._parser.add_argument(
         '--isolated-script-test-launcher-retry-limit', type=int,

testing/scripts/run_telemetry_as_googletest.py

@@ -54,6 +54,9 @@ class TelemetryUnittestAdapter(common.BaseIsolatedScriptArgsAdapter):
   def generate_test_launcher_retry_limit_args(self, retry_limit):
     return ['--retry-limit=%d' % retry_limit]
 
+  def generate_test_repeat_args(self, repeat_count):
+    return ['--repeat=%d' % repeat_count]
+
 
 def main():
   adapter = TelemetryUnittestAdapter()