Move settings_dropdown_menu styling to settings_shared_css.

chrome/browser/resources/settings/site_settings/media_picker.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-dropdown-menu/paper-dropdown-menu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.html">

[dpapad, 2016/07/07 21:03:55]

No longer needed.

[stevenjb, 2016/07/07 21:39:06]

Done.

 <link rel="import" href="chrome://resources/polymer/v1_0/paper-listbox/paper-listbox.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="media-picker">
   <template>
     <style include="settings-shared">
       :host {
         display: block;
       }
-
-      paper-dropdown-menu {
-        --paper-input-container-input: {
-          font-size: inherit;
-        };
-
-        --paper-font-caption: {
-          font-size: inherit;
-        }
-      }
     </style>
     <div class="settings-box" id="picker" hidden>
       <paper-dropdown-menu>
         <paper-listbox id="mediaPicker" class="dropdown-content"
             attr-for-selected="media-picker-value"
             on-iron-activate="onMediaPickerActivate_">
           <template is="dom-repeat" items="[[devices]]">
-            <paper-item media-picker-value$="[[item.id]]">
+            <div class="dropdown-item" media-picker-value$="[[item.id]]">

[dpapad, 2016/07/07 21:03:55]

Let's add role="option" for accessibility.

[stevenjb, 2016/07/07 21:39:06]

Done.

               [[item.name]]
-            </paper-item>
+            </div>
           </template>
         </paper-listbox>
       </paper-dropdown-menu>
     </div>
   </template>
   <script src="media_picker.js"></script>
 </dom-module>