Remove all number. Toggle search and dropdown.

lms/static/coffee/src/discussion/views/discussion_thread_list_view.coffee

@@ -139,6 +139,8 @@ if Backbone?
 
     toggleTopicDrop: (event) =>
       event.stopPropagation()
+      @$(".search").removeClass('is-open')
+      @$(".browse").addClass('is-open')
       @$(".browse").toggleClass('is-dropped')
       if @$(".browse").hasClass('is-dropped')
         @$(".browse-topic-drop-menu-wrapper").show()

lms/templates/discussion/_filter_dropdown.html

@@ -30,7 +30,7 @@
     <ul class="browse-topic-drop-menu">        
         <li>
             <a href="#">
-                <span class="board-name" data-discussion_id='#all'>All</span> <span class="unread">1,248</span>
+                <span class="board-name" data-discussion_id='#all'>All</span>
             </a>
         </li>
         ${render_dropdown(category_map)}