chromium_tests: apply chromium.get_env() when running tests

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

Index: scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Linux.json
diff --git a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Linux.json b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Linux.json
index f9fe409bc4466e14b36cd62a47a9b16b8b64cc1c..332ca7be1ff40200096da1b85b1af7fa62e3a32d 100644
--- a/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Linux.json
+++ b/scripts/slave/recipes/chromium.expected/full_chromium_webkit_WebKit_Linux.json
@@ -376,6 +376,9 @@
       "--output-json",
       "/path/to/tmp/json"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
     "name": "find isolated tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -393,6 +396,9 @@
       "\nimport sys\nprint '*.isolated file for target %s is missing' % sys.argv[1]\nsys.exit(1)\n",
       "browser_tests"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
     "name": "[error] browser_tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -437,6 +443,9 @@
       "--step-name",
       "webkit_tests"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
     "name": "webkit_tests",
     "~followup_annotations": [
       "@@@STEP_TEXT@<br/>Total executed: 9001<br/>@@@"
@@ -460,6 +469,9 @@
       "--gs-acl",
       "public-read"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
     "name": "archive_webkit_tests_results",
     "~followup_annotations": [
       "@@@STEP_LINK@layout_test_results@https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux/571/layout-test-results/results.html@@@",
@@ -473,6 +485,9 @@
       "\nimport sys\nprint '%s wasn\\'t triggered' % sys.argv[1]\nsys.exit(1)\n",
       "browser_tests"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "/creds/service_accounts/service-account-goma-client.json"
+    },
     "name": "[collect error] browser_tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",