Use SVG icon for files-ng elider button

Bug: 1035691
Change-Id: I4aac6e02a90dd7e466f937e7f77a928480fb14e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2087860
Commit-Queue: Alex Danilo <adanilo@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#747113}

ui/file_manager/file_manager/foreground/js/ui/breadcrumb.js

@@ -66,6 +66,15 @@ const breadCrumbTemplate = `
       font-weight: 500;
     }
 
+    button[elider] {
+      -webkit-mask-image: url(../../images/files/ui/menu_ng.svg);
+      -webkit-mask-position: center;
+      -webkit-mask-repeat: no-repeat;
+      background-color: currentColor;
+      min-width: 20px;
+      transform: rotate(90deg);
+    }
+
     button:focus {
       border: 1px solid blue;
       outline: none;