[MD settings] separator line for side nav

chrome/browser/resources/settings/settings_menu/settings_menu.html

 <link rel="import" href="chrome://resources/cr_elements/cr_icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/av-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/device-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/hardware-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/image-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/iron-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icons/social-icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
@@ skipping 48 matching lines @@
       }
 
       paper-submenu div {
         @apply(--layout-center);
         -webkit-margin-start: 24px;
         display: flex;
         font-size: 13px;
         font-weight: 500;
         min-height: 40px;
       }
+
+      .menu-top-margin {
+        margin-top: 8px;

[tommycli, 2016/05/06 18:23:48]

Does it work if you put margin-bottom on every "paper-submenu div" rule?

[dschuyler, 2016/05/06 23:58:24]

Done.

+      }
+
+      .underbar {
+        border-bottom: 1px solid rgba(0, 0, 0, 0.08);

[tommycli, 2016/05/06 18:23:48]

Alan really doesn't want to use the default --settings-separator-line here? If
so maybe add a comment calling this out as a special separator line.

If you follow the above suggestion (about the paper-submenu div rule) you might
need an extra margin on this element also, but I think that's more explicit.

[dschuyler, 2016/05/06 23:58:24]

Done.

+      }
     </style>
     <paper-menu name="root-menu">
       <paper-submenu data-page="basic" id="basicPage">
         <div class="menu-trigger" data-section="" on-tap="openPage_">
           <span i18n-content="basicPageTitle"></span>
           <iron-icon icon="[[arrowState_(basicOpened_)]]" item-icon></iron-icon>
         </div>
         <paper-menu attr-for-selected="data-section" class="menu-content"
             data-page="basic" id="basicMenu">
 <if expr="chromeos">
@@ skipping 26 matching lines @@
             <span i18n-content="defaultBrowser"></span>
           </div>
 </if>
           <div data-section="onStartup" on-tap="openPage_">
             <iron-icon icon="icons:power-settings-new" item-icon></iron-icon>
             <span i18n-content="onStartup"></span>
           </div>
         </paper-menu>
       </paper-submenu>
       <paper-submenu id="advancedPage" data-page="advanced">
-        <div class="menu-trigger" data-section="" on-tap="openPage_">
+        <div class="menu-top-margin menu-trigger" data-section=""
+            on-tap="openPage_">
           <span i18n-content="advancedPageTitle"></span>
           <iron-icon icon="[[arrowState_(advancedOpened_)]]" item-icon>
           </iron-icon>
         </div>
         <paper-menu attr-for-selected="data-section" class="menu-content"
             data-page="advanced" id="advancedMenu">
 <if expr="chromeos">
           <div data-section="dateTime" on-tap="openPage_">
             <iron-icon icon="device:access-time" item-icon></iron-icon>
             <span i18n-content="dateTimePageTitle"></span>
@@ skipping 30 matching lines @@
             <iron-icon icon="icons:build" item-icon></iron-icon>
             <span i18n-content="systemPageTitle"></span>
           </div>
 </if>
           <div data-section="reset" on-tap="openPage_">
             <iron-icon icon="icons:restore" item-icon></iron-icon>
             <span i18n-content="resetPageTitle"></span>
           </div>
         </paper-menu>
       </paper-submenu>
+      <div class="menu-top-margin underbar"></div>
       <paper-submenu on-tap="openPage_">
-        <div class="menu-trigger">
+        <div class="menu-top-margin menu-trigger">
           <span i18n-content="aboutProgram"></span>
         </div>
       </paper-submenu>
     </paper-menu>
   </template>
   <script src="settings_menu.js"></script>
 </dom-module>