MD Settings: Touch up cr-dialog footers

chrome/browser/resources/settings/people_page/people_page.html

 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_expand_button/cr_expand_button.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/icon.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-collapse/iron-collapse.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/neon-animation/neon-animatable.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
@@ skipping 76 matching lines @@
         max-width: 97%;
       }
 
       #googleg-logo {
         background-image: url(../../../../../ui/webui/resources/images/200-logo_googleg.png);
         background-size: cover;
         height: var(--iron-icon-height);
         width: var(--iron-icon-width);
       }
 
-      .footer .settings-box {
+      #disconnectDialog .footer {
+        background-color: transparent;
+        /* TODO(dbeam): should this be a --settings-separator-line? */
+        border-top: 1px solid rgba(0, 0, 0, 0.14);

[tommycli, 2017/02/01 22:46:38]

Spreadsheet calls for 0.12 alpha, but this seems like it should be exactly the
same as top separator line defined here: 

https://cs.chromium.org/chromium/src/ui/webui/resources/cr_elements/cr_dialog...

Has same TODO question as top separator line, but i think we can address those
TODOs later together.

[Dan Beam, 2017/02/02 00:31:05]

aight, maybe --divider-color too

+      }
+
+      #disconnectDialog .footer .settings-box {
         --settings-box-row-padding: 0;
       }
 
       .delete-profile-warning {
         /* In order to line up with the checkbox text. */
         -webkit-padding-start: 36px;
         padding-bottom: 10px;
         padding-top: 10px;
       }
     </style>
@@ skipping 288 matching lines @@
 <if expr="chromeos">
     <template is="dom-if" if="[[showEasyUnlockTurnOffDialog_]]">
       <easy-unlock-turn-off-dialog id="easyUnlockTurnOffDialog"
           on-close="onEasyUnlockTurnOffDialogClose_">
       </easy-unlock-turn-off-dialog>
     </template>
 </if>
   </template>
   <script src="people_page.js"></script>
 </dom-module>