chromium_tests: apply chromium.get_env() when running tests

scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json

Index: scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json
diff --git a/scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json b/scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json
index 78ecb47646f4c05d3504b8c2741dea925f821681..ebdf0a3429a7741295d80370a0017c539a3f4df8 100644
--- a/scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json
+++ b/scripts/slave/recipes/chromium.expected/full_chromium_win_Win8_GN__dbg_.json
@@ -380,6 +380,9 @@
       "--output-json",
       "/path/to/tmp/json"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "find isolated tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -397,6 +400,9 @@
       "\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": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "[error] browser_tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -413,6 +419,9 @@
       "\nimport sys\nprint '%s wasn\\'t triggered' % sys.argv[1]\nsys.exit(1)\n",
       "browser_tests"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "[collect error] browser_tests",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@python.inline@@@@",
@@ -430,6 +439,9 @@
       "--target",
       "Debug"
     ],
+    "env": {
+      "GOMA_SERVICE_ACCOUNT_JSON_FILE": "C:\\creds\\service_accounts\\service-account-goma-client.json"
+    },
     "name": "process_dumps"
   },
   {