MD Settings: Remove last usage of paper-item.

chrome/browser/resources/settings/settings_shared_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 <link rel="import" href="settings_vars_css.html">
 
 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style include="cr-shared-style">
       /* Included here so we don't have to include "iron-positioning" in every
        * stylesheet. See crbug.com/498405. */
       [hidden] {
@@ skipping 35 matching lines @@
       paper-button[toggles][active] {
         background-color: var(--paper-grey-300);
       }
 
       paper-toggle-button {
         @apply(--settings-actionable);
         height: var(--settings-row-min-height);
         width: 31px;
       }
 
-      iron-dropdown .dropdown-content {
-        min-width: 128px;
-        padding: 8px 0;
-      }
-
-      iron-dropdown .dropdown-item:focus {
-        @apply(--cr-selectable-focus);
-      }
-
-      iron-dropdown .dropdown-content {
-        background-color: white;
-        box-shadow: 0 2px 6px var(--paper-grey-500);
-      }
-
-      iron-dropdown .dropdown-content paper-item {
-        @apply(--settings-actionable);
-      }
-
-      iron-dropdown .dropdown-content .dropdown-item[disabled] {
-        opacity: var(--settings-disabled-opacity);
-      }
-
       span ~ a {
         -webkit-margin-start: 4px;
       }
 
       .primary-button,
       .tertiary-button,
       a[href] {
         color: var(--google-blue-700);
       }
 
@@ skipping 242 matching lines @@
       .settings-box .secondary-action {
         -webkit-border-start: var(--settings-separator-line);
         -webkit-margin-start: 20px;
         -webkit-padding-start: 20px;
         align-items: center;
         display: flex;
         flex-shrink: 0;
         height: var(--settings-row-min-height);
       }
 
-      .settings-box paper-item iron-icon {
-        padding: var(--cr-icon-padding);
-      }
-
       /* Helper for a list frame to automatically avoid the separator line. */
       .vertical-list > *:not(:first-of-type) {
         border-top: var(--settings-separator-line);
       }
 
       .settings-checkbox-spacer {
         -webkit-margin-start: calc(
             var(--checkbox-margin-start) +
             var(--checkbox-size) +
             var(--checkbox-spacing));
@@ skipping 36 matching lines @@
       /* Turns the arrow direction downwards, when the bubble is placed above
        * the anchor element */
       .search-bubble-innards.above::after {
         -webkit-transform: rotate(-135deg);
         bottom: -5px;
         top: auto;
       }
     </style>
   </template>
 </dom-module>