Backports EE changes from disabling branch unprotect UI

app/helpers/dropdowns_helper.rb

@@ -41,7 +41,7 @@ module DropdownsHelper
 
   def dropdown_toggle(toggle_text, data_attr, options = {})
     default_label = data_attr[:default_label]
-    content_tag(:button, class: "dropdown-menu-toggle #{options[:toggle_class] if options.key?(:toggle_class)}", id: (options[:id] if options.key?(:id)), type: "button", data: data_attr) do
+    content_tag(:button, disabled: options[:disabled], class: "dropdown-menu-toggle #{options[:toggle_class] if options.key?(:toggle_class)}", id: (options[:id] if options.key?(:id)), type: "button", data: data_attr) do
       output = content_tag(:span, toggle_text, class: "dropdown-toggle-text #{'is-default' if toggle_text == default_label}")
       output << icon('chevron-down')
       output.html_safe

app/views/projects/protected_branches/_branches_list.html.haml

 - can_admin_project = can?(current_user, :admin_project, @project)
 
 = render layout: 'projects/protected_branches/shared/branches_list', locals: { can_admin_project: can_admin_project } do
-  = render partial: 'projects/protected_branches/protected_branch', collection: @protected_branches, locals: { can_admin_project: can_admin_project}
+  = render partial: 'projects/protected_branches/protected_branch', collection: @protected_branches

app/views/projects/protected_branches/shared/_protected_branch.html.haml

@@ -21,4 +21,4 @@
 
   - if can_admin_project
     %td
-      = link_to 'Unprotect', [@project.namespace.becomes(Namespace), @project, protected_branch], data: { confirm: 'Branch will be writable for developers. Are you sure?' }, method: :delete, class: 'btn btn-warning'
+      = link_to 'Unprotect', [@project.namespace.becomes(Namespace), @project, protected_branch], disabled: local_assigns[:disabled], data: { confirm: 'Branch will be writable for developers. Are you sure?' }, method: :delete, class: "btn btn-warning"