Use files in path['checkout'] not resource.

scripts/slave/recipes/chromium.expected/full_chromium_fyi_CrWinClang64_dll_.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[build]\\scripts\\slave\\kill_processes.py"
     ],
     "name": "taskkill"
   },
   {
@@ skipping 373 matching lines @@
     "name": "compile",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output (invalid)@null@@@",
       "@@@STEP_LOG_END@json.output (invalid)@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
-      "RECIPE_MODULE[build::isolate]\\resources\\remove_build_metadata.py",
+      "[BUILDER_CACHE]\\CrWinClang64_dll_\\src\\tools\\determinism\\remove_build_metadata.py",
       "--build-dir",
-      "[BUILDER_CACHE]\\CrWinClang64_dll_\\src\\out\\Release_x64",
-      "--src-dir",
-      "[BUILDER_CACHE]\\CrWinClang64_dll_\\src"
+      "[BUILDER_CACHE]\\CrWinClang64_dll_\\src\\out\\Release_x64"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "remove_build_metadata"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::isolate]\\resources\\isolate.py",
       "[BUILDER_CACHE]\\CrWinClang64_dll_\\src\\tools\\swarming_client",
@@ skipping 68 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@CrWinClang64(dll) tester@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]