MD Settings: Internet: Reduce use of hidden for complex sections.

chrome/browser/resources/settings/internet_page/network_summary_item.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-spinner/paper-spinner.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_expand_button/cr_expand_button.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_network_list.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_network_list_network_item.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module name="network-summary-item">
   <template>
     <style include="settings-shared">
       :host {
         --cr-network-icon-mixin: {
           height: 24px;
           left: -4px;
           width: 24px;
         }
         --cr-network-name-mixin: {
           font-size: inherit;
         };
         --cr-network-state-mixin: {
           @apply(--settings-secondary);
           font-size: inherit;
         };
       }
 
+      paper-spinner {
+        -webkit-margin-start: 20px;
+      }
+
+      .button-row {
+        align-items: center;
+        border-top: var(--settings-separator-line);
+        display: flex;
+        min-height: var(--settings-row-min-height);
+      }
+
       #buttons {
         align-items: center;
       }
 
-      .invisible {
-        visibility: hidden;
-      }
-
-      paper-spinner {
-        -webkit-margin-start: 20px;
-      }
-
       #deviceEnabledButton {
         -webkit-margin-start: 10px;
       }
 
       #networkList {
         margin: 5px 0 10px;
         max-height: 400px;
       }
     </style>
-    <div class="settings-box two-line" hidden$="[[isHidden]]">
+    <div class="settings-box two-line">
       <div id="details" class="start" on-tap="onDetailsTap_" actionable>
-        <cr-network-list-network-item id="detailsItem" network-state="[[networkState]]" show-buttons>
+        <cr-network-list-network-item id="detailsItem"
+            network-state="[[activeNetworkState]]" show-buttons>
         </cr-network-list-network-item>
         <paper-spinner active="[[showScanning_(deviceState, expanded)]]">
         </paper-spinner>
       </div>
       <div>
         <div id="buttons" class="layout horizontal">
-          <cr-expand-button id="expandListButton"
-              class$="[[getExpandButtonClass_(deviceState, networkStateList)]]"
-              expanded="{{expanded}}">
-          </cr-expand-button>
-          <paper-toggle-button id="deviceEnabledButton"
-              checked="[[deviceIsEnabled_(deviceState)]]"
-              class$="[[getDeviceEnabledButtonClass_(deviceState)]]"
-              on-tap="onDeviceEnabledTap_">
-          </paper-toggle-button>
+          <template is="dom-if"
+              if="[[expandIsVisible_(deviceState, networkStateList)]]">
+            <cr-expand-button id="expandListButton" expanded="{{expanded}}">
+            </cr-expand-button>
+          </template>
+          <template is="dom-if" if="[[enableIsVisible_(deviceState)]]">
+            <paper-toggle-button  id="deviceEnabledButton"
+                checked="[[deviceIsEnabled_(deviceState)]]"
+                on-tap="onDeviceEnabledTap_">
+            </paper-toggle-button>
+          </template>
         </div>
       </div>
     </div>
     <template is="dom-if" if="[[expanded]]">
       <div class="list-frame">
         <cr-network-list id="networkList"
             max-height="[[maxHeight]]"
             networks="[[networkStateList]]"
             opened="{{expanded}}"
             show-buttons>
         </cr-network-list>
-        <div class="layout horizontal">
-          <paper-button
-              hidden$="[[!showKnownNetworks_(networkState, expanded)]]"
-              on-tap="onKnownNetworksTap_">
-            Known networks
-          </paper-button>
-        </div>
+        <template is="dom-if"
+            if="[[knownNetworksIsVisible_(activeNetworkState)]]">
+          <div class="button-row">
+            <paper-button on-tap="onKnownNetworksTap_">
+              Known networks
+            </paper-button>
+          </div>
+        </template>
       </div>
     </template>
   </template>
   <script src="network_summary_item.js"></script>
 </dom-module>