MD Settings: fix overflow scrolling for <settings-dialog>

chrome/browser/resources/settings/settings_dialog.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-dialog-behavior/paper-dialog-behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-dialog-behavior/paper-dialog-shared-styles.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 
 <dom-module id="settings-dialog">
   <template>
     <style include="paper-dialog-shared-styles"></style>
     <style>
-      .body-content {
+      .body-container {
         display: flex;
         flex-direction: column;
         min-height: 120px;
+        overflow-y: auto;
       }
 
       .dialog-content {
         -webkit-padding-end: 0;
         -webkit-padding-start: 0;
         margin-bottom: 0;
         margin-top: 0;
       }
 
       .footer-container {
         margin: 0;
         padding: 0;
       }
 
-      .top-row {
+      .title-container {
         align-items: center;
         border-bottom: 1px solid rgba(0, 0, 0, 0.14);
         display: flex;
         min-height: 52px;
       }
 
       paper-icon-button {
         height: 20px;
         margin: 16px;
         padding: 0;
         width: 20px;
       }
 
       :host {
         border-radius: 2px;
         max-width: 800px;
         min-width: 512px;
-        overflow: auto;
       }
 
       :host ::content .body,
       :host ::content .footer,
       :host ::content paper-button {
         font-size: 92.86%; /* (13px / 14px) * 100 */
       }
 
       :host ::content .body {
         margin: 12px 0 24px 0;
       }
 
-      :host ::content .button-container {
+      :host ::content .buttons {
         -webkit-padding-end: 16px;
         -webkit-padding-start: 16px;
         display: flex;
         justify-content: flex-end;
         margin-bottom: 12px;
       }
 
-      :host ::content .button-container .cancel-button {
+      :host ::content .buttons .cancel-button {
         -webkit-margin-end: 8px;
         color: var(--paper-grey-600);
       }
 
       :host ::content .footer {
         background-color: var(--paper-grey-200);
         margin: 0;
         padding: 20px;
       }
 
@@ skipping 12 matching lines @@
       }
 
       :host ::content .body,
       :host ::content .title {
         -webkit-padding-end: 24px;
         -webkit-padding-start: 24px;
         flex: 1;
       }
     </style>
     <div class="dialog-content">
-      <div class="top-row">
+      <div class="title-container">
         <content select=".title"></content>
         <paper-icon-button icon="cr:clear" on-tap="cancel" id="close">
         </paper-icon-button>
       </div>
-      <div class="body-content">
+      <div class="body-container">
         <content select=".body"></content>
-        <content select=".button-container"></content>
+      </div>
+      <div class="button-container">
+        <content select=".buttons"></content>
       </div>
     </div>
     <div class="footer-container">
       <content select=".footer"></content>
     </div>
   </template>
   <script src="settings_dialog.js"></script>
 </dom-module>