Add OWNERS for dev_ui_browser_resources

This is a follow up from https://crrev.com/c/2055597
to add webui to the owners for the resources file.

Change-Id: I63ab01298933c1c81a3c35d462571563066d28e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2062929Reviewed-by: Theresa  <twellington@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742230}

chrome/browser/OWNERS

@@ -18,6 +18,7 @@ per-file *_android.*=file://chrome/browser/android/OWNERS
 per-file *.java=file://chrome/browser/android/OWNERS
 
 per-file browser_resources.grd=file://ui/webui/PLATFORM_OWNERS
+per-file dev_ui_browser_resources.grd=file://ui/webui/PLATFORM_OWNERS
 
 per-file browser_close_manager_browsertest.cc=creis@chromium.org