Updating swarming api to check for chartjson results from a finished

scripts/slave/recipes/chromium.expected/dynamic_swarmed_isolated_script_test_win_non_gpu.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
@@ skipping 365 matching lines @@
       "--tag",
       "purpose:CI",
       "--tag",
       "purpose:post-commit",
       "--tag",
       "slavename:TestSlavename",
       "--tag",
       "stepname:telemetry_gpu_unittests on Windows",
       "eeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
       "--",
-      "--isolated-script-test-output=${ISOLATED_OUTDIR}/output.json"
+      "--isolated-script-test-output=${ISOLATED_OUTDIR}/output.json",
+      "--isolated-script-test-chartjson-output=${ISOLATED_OUTDIR}/chartjson-output.json"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
     },
     "name": "[trigger] telemetry_gpu_unittests on Windows",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"base_task_name\": \"telemetry_gpu_unittests/Windows/eeeeeeeeee/Win7 Tests (1)/571\", @@@",
       "@@@STEP_LOG_LINE@json.output@  \"tasks\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"telemetry_gpu_unittests/Windows/eeeeeeeeee/Win7 Tests (1)/571\": {@@@",
@@ skipping 41 matching lines @@
       "{\"base_task_name\": \"telemetry_gpu_unittests/Windows/eeeeeeeeee/Win7 Tests (1)/571\", \"tasks\": {\"telemetry_gpu_unittests/Windows/eeeeeeeeee/Win7 Tests (1)/571\": {\"shard_index\": 0, \"task_id\": \"10000\", \"view_url\": \"https://chromium-swarm.appspot.com/user/task/10000\"}}}",
       "--task-output-dir",
       "/path/to/tmp/"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
     },
     "name": "telemetry_gpu_unittests on Windows",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@outdir_json@{@@@",
+      "@@@STEP_LOG_LINE@outdir_json@  \"0\\\\chartjson-output.json\": \"{\\\"dummy\\\": \\\"dummy0\\\", \\\"charts\\\": [{\\\"entry2\\\": \\\"chart2\\\", \\\"entry1\\\": \\\"chart1\\\"}]}\", @@@",
       "@@@STEP_LOG_LINE@outdir_json@  \"0\\\\output.json\": \"{\\\"successes\\\": [\\\"test1.Test1\\\", \\\"test2.Test2\\\"], \\\"failures\\\": [], \\\"valid\\\": true, \\\"times\\\": {\\\"test2.Test2\\\": 0.1, \\\"test1.Test1\\\": 0.1}}\", @@@",
       "@@@STEP_LOG_LINE@outdir_json@  \"summary.json\": \"{\\\"shards\\\": [{\\\"internal_failure\\\": false, \\\"failure\\\": false}]}\"@@@",
       "@@@STEP_LOG_LINE@outdir_json@}@@@",
       "@@@STEP_LOG_END@outdir_json@@@",
       "@@@STEP_LINK@shard #0@https://chromium-swarm.appspot.com/user/task/10000@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\process_dumps.py",
       "--target",
       "Release"
     ],
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
     },
     "name": "process_dumps"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]