Remove styles for dueToRebase chunks

While the due_to_rebase signal gives false-positives and false-negatives
(Issue 6583) do not style the marked chunks differently.

Change-Id: Ic716dcf259c4f4f0ef09510e37ce744c1d4082e0
diff --git a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
index 5319ace..6aae8d1 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff/gr-diff.html
@@ -142,20 +142,6 @@
       .content.remove {
         background-color: var(--light-remove-highlight-color);
       }
-      .dueToRebase .content.add .intraline,
-      .delta.total.dueToRebase .content.add {
-        background-color: var(--dark-rebased-add-highlight-color);
-      }
-      .dueToRebase .content.add {
-        background-color: var(--light-rebased-add-highlight-color);
-      }
-      .dueToRebase .content.remove .intraline,
-      .delta.total.dueToRebase .content.remove {
-        background-color: var(--dark-rebased-remove-highlight-color);
-      }
-      .dueToRebase .content.remove {
-        background-color: var(--light-rebased-remove-highlight-color);
-      }
       .content .contentText:after {
         /* Newline, to ensure all lines are one line-height tall. */
         content: '\A';