Files app: Change loading bar to blue for FilesNg

No-try: true
Bug: 1002395
Change-Id: I3ded1615a2a0709a496b6fd64fce91c169fb6b62
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2100170
Commit-Queue: Luciano Pacheco <lucmult@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Auto-Submit: Luciano Pacheco <lucmult@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Reviewed-by: Alex Danilo <adanilo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749555}

ui/file_manager/file_manager/foreground/css/file_manager.css

@@ -1488,6 +1488,10 @@ body.check-select #read-only-indicator {
   top: 40px;
 }
 
+body.files-ng .loading-indicator {
+    --paper-progress-active-color: var(--google-blue-600);
+}
+
 body.files-ng .list-view .loading-indicator {
   top: 48px;
 }