Add "ui-select-dropdown" class to identify the dropdown container.

Author: JeromeLam

src/bootstrap/choices.tpl.html

@@ -1,4 +1,4 @@
-<ul class="ui-select-choices ui-select-choices-content dropdown-menu"
+<ul class="ui-select-choices ui-select-choices-content ui-select-dropdown dropdown-menu"
     role="listbox"
     ng-show="$select.items.length > 0">
   <li class="ui-select-choices-group" id="ui-select-choices-{{ $select.generatedId }}" >

src/select2/select-multiple.tpl.html

@@ -25,8 +25,8 @@
         ondrop="return false;">
     </li>
   </ul>
-  <div class="select2-drop select2-with-searchbox select2-drop-active"
+  <div class="ui-select-dropdown select2-drop select2-with-searchbox select2-drop-active"
        ng-class="{'select2-display-none': !$select.open}">
     <div class="ui-select-choices"></div>
   </div>
-</div>
+</div>

src/select2/select.tpl.html

@@ -4,7 +4,7 @@
                 'select2-container-active': $select.focus,
                 'select2-allowclear': $select.allowClear && !$select.isEmpty()}">
   <div class="ui-select-match"></div>
-  <div class="select2-drop select2-with-searchbox select2-drop-active"
+  <div class="ui-select-dropdown select2-drop select2-with-searchbox select2-drop-active"
        ng-class="{'select2-display-none': !$select.open}">
     <div class="select2-search" ng-show="$select.searchEnabled">
       <input type="text" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"

src/selectize/choices.tpl.html

@@ -1,4 +1,4 @@
-<div ng-show="$select.open" class="ui-select-choices selectize-dropdown single">
+<div ng-show="$select.open" class="ui-select-choices ui-select-dropdown selectize-dropdown single">
   <div class="ui-select-choices-content selectize-dropdown-content">
     <div class="ui-select-choices-group optgroup" role="listbox">
       <div ng-show="$select.isGrouped" class="ui-select-choices-group-label optgroup-header" ng-bind="$group.name"></div>