Bookmarks WebUI: Increase padding of subfolders

Bug: 999094
Change-Id: I830363d723b495669eb22c0ed30c32ffb41182e6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1783664Reviewed-by: calamity <calamity@chromium.org>
Commit-Queue: John Lee <johntlee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693394}

chrome/browser/resources/bookmarks/folder_node.html

@@ -24,7 +24,7 @@
         height: 40px;
         min-width: fit-content;
         overflow: hidden;
-        padding-inline-start: calc(var(--node-depth, 0) * 10px);
+        padding-inline-start: calc(var(--node-depth, 0) * 15px);
       }
 
       #arrow {