Update _mr_title.html.haml button css

app/assets/stylesheets/framework/buttons.scss

@@ -200,8 +200,7 @@
     @include btn-orange;
   }
 
-  &.btn-close,
-  &.btn-close-color {
+  &.btn-close {
     @include btn-outline($white, $orange-500, $orange-500, $orange-50, $orange-600, $orange-600, $orange-100, $orange-700, $orange-700);
   }
 

app/views/projects/merge_requests/_mr_title.html.haml

@@ -50,4 +50,4 @@
       - if can_update_merge_request && !are_close_and_open_buttons_hidden
         = render 'shared/issuable/close_reopen_draft_report_toggle', issuable: @merge_request
       - elsif !@merge_request.merged?
-        = link_to _('Report abuse'), new_abuse_report_path(user_id: @merge_request.author.id, ref_url: issuable_url(@merge_request)), class: 'd-none d-md-block btn btn-grouped btn-close-color', title: _('Report abuse')
+        = link_to _('Report abuse'), new_abuse_report_path(user_id: @merge_request.author.id, ref_url: issuable_url(@merge_request)), class: 'gl-display-none gl-display-md-block gl-button btn btn-warning-secondary', title: _('Report abuse')