Move revert link to the MR widget section plus some refactor.

app/helpers/commits_helper.rb

@@ -123,14 +123,14 @@ module CommitsHelper
     )
   end
 
-  def revert_commit_link(show_modal_condition, continue_to_path)
+  def revert_commit_link(show_modal_condition, continue_to_path, btn_class: nil)
     return unless current_user
 
     if show_modal_condition
       link_to('Revert', '#modal-revert-commit',
         'data-target' => '#modal-revert-commit',
         'data-toggle' => 'modal',
-        class: 'btn btn-grouped btn-close',
+        class: "btn btn-close btn-#{btn_class}",
         title: 'Create merge request to revert commit'
       )
     else

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

@@ -18,6 +18,3 @@
           Edit
       - if @merge_request.closed?
         = link_to 'Reopen', merge_request_path(@merge_request, merge_request: {state_event: :reopen }), method: :put, class: 'btn btn-nr btn-grouped btn-reopen reopen-mr-link', title: "Reopen merge request"
-
-    - if @merge_request.merged? && @merge_request.merge_commit_sha.present?
-      = revert_commit_link(can_update_merge_request?, namespace_project_merge_request_path(@project.namespace, @project, @merge_request))

app/views/projects/merge_requests/widget/_merged.html.haml

@@ -6,6 +6,8 @@
       - if @merge_request.merge_event
         by #{link_to_member(@project, @merge_request.merge_event.author, avatar: true)}
         #{time_ago_with_tooltip(@merge_request.merge_event.created_at)}
+      - if @merge_request.merge_commit_sha.present?
+        = revert_commit_link(can_update_merge_request?, namespace_project_merge_request_path(@project.namespace, @project, @merge_request), btn_class: 'sm')
     %div
       - if !@merge_request.source_branch_exists? || (params[:delete_source] == 'true')
         The changes were merged into