To solve issue:
1. Need to check whether tests were ran (check Action -> ActionResult -> TestsCount) and if the number is 0 and Action -> ActionResult -> ErrorCount is not 0, it means tests didn't start. Update test_result['attempts'] list by adding kvp 'TESTS_DID_NOT_START': []
2. In LaunchCommand check if 'TESTS_DID_NOT_START' is in last test_results and if yes, repeat command. To decide which command to repeat checks whether init_command is equal to last used cmd_list command.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8aa18875734b9ce41457d5d2a7c1a8a1cf3e6347

commit 8aa18875734b9ce41457d5d2a7c1a8a1cf3e6347
Author: git config --global <monufriienko@chromium.org>
Date: Thu Dec 20 01:25:59 2018

Fixed issue in Info.plist/TestSummary parsing

Before the fix SimulatorParallelTestRunner fails during Info.plist/TestSummary parsing
if xcodebuild doesn't start properly (some fields are empty if the error raises).

Bug: 916620
Change-Id: Ia3c6c55f82df2dd49b4966865b301176cdce1076
Reviewed-on: https://chromium-review.googlesource.com/c/1384939
Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
Reviewed-by: Sergey Berezin <sergeyberezin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618061}
[modify] https://crrev.com/8aa18875734b9ce41457d5d2a7c1a8a1cf3e6347/ios/build/bots/scripts/xcodebuild_runner.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4d2214e381bd88e4065495a89f0b0b2c82706832

commit 4d2214e381bd88e4065495a89f0b0b2c82706832
Author: git config --global <monufriienko@chromium.org>
Date: Tue Jan 08 01:32:44 2019

Fixed re-run command when test didn't start for the previous attempt.

Bug: 916620
Change-Id: Ia18ad6633672412a061e027f512fc72486c827b0
Reviewed-on: https://chromium-review.googlesource.com/c/1398506
Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
Reviewed-by: Sergey Berezin <sergeyberezin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620568}
[modify] https://crrev.com/4d2214e381bd88e4065495a89f0b0b2c82706832/ios/build/bots/scripts/xcodebuild_runner.py
[modify] https://crrev.com/4d2214e381bd88e4065495a89f0b0b2c82706832/ios/build/bots/scripts/xcodebuild_runner_test.py