MDL-57321 theme_boost: Use div instead of span for dropdown items

theme/boost/templates/core/action_menu_trigger.mustache

@@ -17,10 +17,10 @@
 {{!
     Action menu trigger.
 }}
-<span class="dropdown">
+<div class="dropdown">
     <a href="#" class="dropdown-toggle" id="dropdown-{{instance}}" title="{{title}}" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">{{{actiontext}}}{{{menutrigger}}}{{#icon}}{{> core/pix_icon}}{{/icon}}{{#rawicon}}{{{.}}}{{/rawicon}}{{#menutrigger}}<b class="caret"></b>{{/menutrigger}}</a>
     {{#secondary}}
-        <span class="dropdown-menu dropdown-menu-right {{classes}}"{{#attributes}} {{name}}="{{value}}"{{/attributes}} aria-labelledby="dropdown-{{instance}}">
+        <div class="dropdown-menu dropdown-menu-right {{classes}}"{{#attributes}} {{name}}="{{value}}"{{/attributes}} aria-labelledby="dropdown-{{instance}}">
             {{#items}}{{!
                 }}{{#actionmenulink}}<a href="{{url}}" class="dropdown-item {{classes}}"{{#attributes}} {{name}}={{#quote}}{{value}}{{/quote}}{{/attributes}} {{#showtext}}aria-labelledby="actionmenuaction-{{instance}}"{{/showtext}}>{{#icon}}{{>core/pix_icon}}{{/icon}}{{#showtext}}<span class="menu-action-text" id="actionmenuaction-{{instance}}">{{{text}}}</span>{{/showtext}}</a>{{/actionmenulink}}{{!
                 }}{{#actionmenufiller}}<div class="dropdown-divider"></div>{{/actionmenufiller}}{{!
@@ -28,4 +28,4 @@
             }}{{/items}}
         </div>
     {{/secondary}}
-</span>
+</div>

theme/boost/templates/core/custom_menu_item.mustache

 {{^divider}}
 {{#haschildren}}
-<span class="dropdown nav-item">
+<div class="dropdown nav-item">
     <a class="dropdown-toggle nav-link" id="drop-down-{{uniqid}}" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false" href="#">
         {{text}}
     </a>
@@ -14,7 +14,7 @@
             {{/divider}}
         {{/children}}
     </div>
-</span>
+</div>
 {{/haschildren}}
 {{^haschildren}}
 <a class="nav-item nav-link" href="{{{url}}}" {{#title}}title="{{{title}}}"{{/title}}>{{text}}</a>