Merge "Fix code comment position with Firefox" into stable-3.10
diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
index 8b333e6..1de8298 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
@@ -75,6 +75,8 @@
   gr-diff-element {
     /* for gr-selection-action-box positioning */
     position: relative;
+    /* Firefox requires a block to position child elements absolutely */
+    display: block;
   }
   gr-diff-element gr-selection-action-box {
     /* Needs z-index to appear above wrapped content, since it's inserted