Revert "build: roll infra_paths changes"

scripts/slave/recipes/infra/infra_repo_trybot.expected/basic.json

 [
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_MODULE[depot_tools::bot_update]/resources/bot_update.py",
       "--master",
       "tryserver.chromium.linux",
       "--builder",
       "infra_tester",
       "--slave",
       "TestSlavename",
       "--spec",
-      "cache_dir = '[ROOT]/b/build/slave/cache_dir'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'infra', 'url': 'https://chromium.googlesource.com/infra/infra.git'}]",
+      "cache_dir = '[GIT_CACHE]'\nsolutions = [{'deps_file': '.DEPS.git', 'managed': True, 'name': 'infra', 'url': 'https://chromium.googlesource.com/infra/infra.git'}]",
       "--root",
       "infra",
       "--revision_mapping_file",
       "{\"infra\": \"got_revision\"}",
       "--git-cache-dir",
-      "[ROOT]/b/build/slave/cache_dir",
+      "[GIT_CACHE]",
       "--issue",
       "12853011",
       "--patchset",
       "1",
       "--rietveld_server",
       "https://codereview.chromium.org",
       "--output_json",
       "/path/to/tmp/json",
       "--revision",
       "infra@HEAD",
       "--force",
       "--output_manifest"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "bot_update",
     "~followup_annotations": [
       "@@@STEP_TEXT@Some step text@@@",
       "@@@STEP_LOG_LINE@json.output@{@@@",
       "@@@STEP_LOG_LINE@json.output@  \"did_run\": true, @@@",
       "@@@STEP_LOG_LINE@json.output@  \"fixed_revisions\": {@@@",
       "@@@STEP_LOG_LINE@json.output@    \"infra\": \"HEAD\"@@@",
@@ skipping 23 matching lines @@
       "git",
       "-c",
       "user.email=commit-bot@chromium.org",
       "-c",
       "user.name=The Commit Bot",
       "commit",
       "-a",
       "-m",
       "Committed patch"
     ],
-    "cwd": "[CWD]/infra",
+    "cwd": "[SLAVE_BUILD]/infra",
     "name": "commit git patch"
   },
   {
     "cmd": [
       "python",
       "-u",
       "RECIPE_PACKAGE_REPO[depot_tools]/gclient.py",
       "runhooks"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "env": {
       "PATH": "%(PATH)s:RECIPE_PACKAGE_REPO[depot_tools]"
     },
     "name": "gclient runhooks"
   },
   {
     "cmd": [
       "git",
       "diff",
       "--name-only",
       "HEAD",
       "HEAD~"
     ],
-    "cwd": "[CWD]/infra",
+    "cwd": "[SLAVE_BUILD]/infra",
     "name": "get change list",
     "stdout": "/path/to/tmp/",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@change list@infra/stuff.py@@@",
       "@@@STEP_LOG_LINE@change list@go/src/infra/stuff.go@@@",
       "@@@STEP_LOG_END@change list@@@"
     ]
   },
   {
     "cmd": [
       "python",
       "-u",
       "test.py",
       "test"
     ],
-    "cwd": "[CWD]/infra",
+    "cwd": "[SLAVE_BUILD]/infra",
     "name": "python tests"
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[CWD]/infra/go/env.py"
+      "[SLAVE_BUILD]/infra/go/env.py"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "go bootstrap"
   },
   {
     "cmd": [
       "python",
       "-u",
-      "[CWD]/infra/go/env.py",
+      "[SLAVE_BUILD]/infra/go/env.py",
       "python",
-      "[CWD]/infra/go/test.py"
+      "[SLAVE_BUILD]/infra/go/test.py"
     ],
+    "cwd": "[SLAVE_BUILD]",
     "name": "go tests"
   },
   {
     "name": "$result",
     "recipe_result": null,
     "status_code": 0
   }
 ]