Merge branch 'z-index-tools' into 'master'

Review Tools: Add large z-index to toolbar

See merge request gitlab-org/gitlab-ce!30583

app/assets/javascripts/visual_review_toolbar/styles/toolbar.css

@@ -48,6 +48,7 @@
   font-size: .8rem;
   font-weight: 400;
   color: #2e2e2e;
+  z-index: 9999; /* toolbar should always be on top */
 }
 
 .gitlab-wrapper-open {

changelogs/unreleased/z-index-tools.yml

+---
+title: 'Review Tools: Add large z-index to toolbar'
+merge_request: 30583
+author:
+type: fixed