Fix path separators for Windows in presubmit

This should now properly support autoroll CLs to no longer having
to disable this check.

[email protected]

Bug: none
Change-Id: I079b76db2e8cc3e2990894d1e58227ca01e8c578
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2822644
Commit-Queue: Tim van der Lippe <[email protected]>
Commit-Queue: Alex Rudenko <[email protected]>
Auto-Submit: Tim van der Lippe <[email protected]>
Reviewed-by: Alex Rudenko <[email protected]>
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index d6b20d1..5f83483 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -36,15 +36,6 @@
 import six
 import time
 
-EXCLUSIVE_CHANGE_DIRECTORIES = [
-    ['third_party', 'v8', 'front_end/generated'],
-    [
-        'node_modules', 'package.json', 'package-lock.json',
-        'scripts/deps/manage_node_deps.py'
-    ],
-    ['OWNERS', 'config/owner'],
-]
-
 AUTOROLL_ACCOUNT = "devtools-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com"
 
 
@@ -85,6 +76,20 @@
             if IsParentDir(file, dir):
                 return True
 
+    EXCLUSIVE_CHANGE_DIRECTORIES = [
+        [
+            'third_party', 'v8',
+            input_api.os_path.join('front_end', 'generated')
+        ],
+        [
+            'node_modules',
+            'package.json',
+            'package-lock.json',
+            input_api.os_path.join('scripts', 'deps', 'manage_node_deps.py'),
+        ],
+        ['OWNERS', input_api.os_path.join('config', 'owner')],
+    ]
+
     affected_files = input_api.LocalPaths()
     num_affected = len(affected_files)
     for dirs in EXCLUSIVE_CHANGE_DIRECTORIES: