chromium.run_mb: set cwd to checkout

scripts/slave/recipes/v8.expected/full_client_v8_V8_Linux___predictable_bisect.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "client.v8",
       "--builder",
       "V8 Linux - predictable",
@@ skipping 137 matching lines @@
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--gyp-script=gypfiles/gyp_v8",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "generate_build_files",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@stdout@some line@@@",
       "@@@STEP_LOG_LINE@stdout@GYP_DEFINES='target_arch=x64 cool_flag=a=1'@@@",
       "@@@STEP_LOG_LINE@stdout@moar@@@",
       "@@@STEP_LOG_END@stdout@@@"
@@ skipping 40 matching lines @@
       "-m",
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[mb config]",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "[SLAVE_BUILD]/v8/out/gn"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "generate_build_files with gn (fyi)"
   },
   {
     "cmd": [
       "python",
       "-u",
       "[SLAVE_BUILD]/v8/tools/gyp_flag_compare.py",
@@ skipping 477 matching lines @@
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--gyp-script=gypfiles/gyp_v8",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a0.generate_build_files",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@stdout@some line@@@",
       "@@@STEP_LOG_LINE@stdout@GYP_DEFINES='target_arch=x64 cool_flag=a=1'@@@",
       "@@@STEP_LOG_LINE@stdout@moar@@@",
@@ skipping 45 matching lines @@
       "-m",
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[mb config]",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "[SLAVE_BUILD]/v8/out/gn"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a0.generate_build_files with gn (fyi)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
@@ skipping 260 matching lines @@
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--gyp-script=gypfiles/gyp_v8",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a2.generate_build_files",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@stdout@some line@@@",
       "@@@STEP_LOG_LINE@stdout@GYP_DEFINES='target_arch=x64 cool_flag=a=1'@@@",
       "@@@STEP_LOG_LINE@stdout@moar@@@",
@@ skipping 45 matching lines @@
       "-m",
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[mb config]",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "[SLAVE_BUILD]/v8/out/gn"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a2.generate_build_files with gn (fyi)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
@@ skipping 293 matching lines @@
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[SLAVE_BUILD]/v8/infra/mb/mb_config.pyl",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "--gyp-script=gypfiles/gyp_v8",
       "//out/Release"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a1.generate_build_files",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
       "@@@STEP_LOG_LINE@stdout@some line@@@",
       "@@@STEP_LOG_LINE@stdout@GYP_DEFINES='target_arch=x64 cool_flag=a=1'@@@",
       "@@@STEP_LOG_LINE@stdout@moar@@@",
@@ skipping 45 matching lines @@
       "-m",
       "client.v8",
       "-b",
       "V8 Linux - predictable",
       "--config-file",
       "[mb config]",
       "--goma-dir",
       "[CACHE]/cipd/goma",
       "[SLAVE_BUILD]/v8/out/gn"
     ],
+    "cwd": "[SLAVE_BUILD]/v8",
     "env": {
       "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
     },
     "name": "Bisect a1.generate_build_files with gn (fyi)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
     "cmd": [
@@ skipping 111 matching lines @@
       "@@@STEP_LINK@a2@https://chromium.googlesource.com/v8/v8/+/a2@@@"
     ]
   },
   {
     "name": "$result",
     "reason": "Failures or flakes in build.",
     "recipe_result": null,
     "status_code": 1
   }
 ]