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

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

 [
   {
     "cmd": [
       "python",
       "-u",
       "\nimport sys, os\npath = sys.argv[1]\nmode = int(sys.argv[2])\nif not os.path.isdir(path):\n  if os.path.exists(path):\n    print \"%s exists but is not a dir\" % path\n    sys.exit(1)\n  os.makedirs(path, mode)\n",
       "[BUILDER_CACHE]/mac_layout",
       "511"
     ],
     "name": "makedirs checkout path",
@@ skipping 369 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]/mac_layout/src/tools/determinism/remove_build_metadata.py",
       "--build-dir",
-      "[BUILDER_CACHE]/mac_layout/src/out/Release",
-      "--src-dir",
-      "[BUILDER_CACHE]/mac_layout/src"
+      "[BUILDER_CACHE]/mac_layout/src/out/Release"
     ],
     "cwd": "[SLAVE_BUILD]",
     "name": "remove_build_metadata"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[build::isolate]/resources/isolate.py",
       "[BUILDER_CACHE]/mac_layout/src/tools/swarming_client",
@@ skipping 89 matching lines @@
     "~followup_annotations": [
       "@@@STEP_TEXT@WebKit Mac10.10<br />WebKit Mac10.11@@@"
     ]
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]