Add counting the number of CPU's in goma module

scripts/slave/recipes/libyuv/libyuv.expected/tryserver_libyuv_linux_ubsan_vptr.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "tryserver.libyuv",
       "--builder",
       "linux_ubsan_vptr",
@@ skipping 92 matching lines @@
       "@@@STEP_LOG_LINE@json.output@    }@@@",
       "@@@STEP_LOG_LINE@json.output@  ]@@@",
       "@@@STEP_LOG_LINE@json.output@}@@@",
       "@@@STEP_LOG_END@json.output@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
+      "\nimport multiprocessing\n\ntry:\n  jobs = min(200, multiprocessing.cpu_count() * 10)\nexcept NotImplementedError:\n  jobs = 50\n\nprint jobs\n"
+    ],
+    "name": "ensure_goma.get the number of cpus",
+    "stdout": "/path/to/tmp/",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@python.inline@@@@",
+      "@@@STEP_LOG_LINE@python.inline@import multiprocessing@@@",
+      "@@@STEP_LOG_LINE@python.inline@@@@",
+      "@@@STEP_LOG_LINE@python.inline@try:@@@",
+      "@@@STEP_LOG_LINE@python.inline@  jobs = min(200, multiprocessing.cpu_count() * 10)@@@",
+      "@@@STEP_LOG_LINE@python.inline@except NotImplementedError:@@@",
+      "@@@STEP_LOG_LINE@python.inline@  jobs = 50@@@",
+      "@@@STEP_LOG_LINE@python.inline@@@@",
+      "@@@STEP_LOG_LINE@python.inline@print jobs@@@",
+      "@@@STEP_LOG_END@python.inline@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "python",
+      "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "runhooks"
     ],
     "cwd": "[SLAVE_BUILD]/src",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json",
       "GYP_DEFINES": "clang=1 component=static_library dcheck_always_on=1 fastbuild=1 gomadir='[CACHE]/cipd/goma' release_extra_cflags=-fno-sanitize-recover=undefined target_arch=x64 ubsan_vptr=1 use_goma=1",
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
@@ skipping 78 matching lines @@
       "libyuv_unittest"
     ],
     "name": "libyuv_unittest"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]