MD Settings: long dialog body should have overscroll line.

chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html

Index: chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html
diff --git a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html
index 93472c082c91fe5e2e3c5c990cf0ad9237a15240..099ed17e927277b204a5408cf50e0d894ed161ba 100644
--- a/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html
+++ b/chrome/browser/resources/settings/clear_browsing_data_dialog/clear_browsing_data_dialog.html
@@ -19,7 +19,6 @@
       }
 
       #dialog .button-container {
-        border-top: 1px solid rgba(0, 0, 0, 0.14);
         margin-top: 0;
         padding-top: 10px;
       }
@@ -89,17 +88,22 @@
        * Replace the bottom margin with padding to avoid the gap between
        * the scrollbar and the bottom separator. */
       @media all and (max-height: 724px) {
+        #dialog {
+          /* crbug.com/652027: Show four and a *half* items in the list. */
+          --cr-dialog-body-container: {
+            max-height: 280px; 
+          };
+        }
+
         #dialog .body {
           margin-bottom: 0;
-          /* crbug.com/652027: Show four and a *half* items in the list. */
-          max-height: 280px;
-          overflow-y: scroll;
           padding-bottom: 12px;
         }
       }
     </style>
 
-    <dialog is="cr-dialog" id="dialog" close-text="$i18n{close}" ignore-popstate>
+    <dialog is="cr-dialog" id="dialog" close-text="$i18n{close}"
+        show-scroll-borders ignore-popstate>
       <div class="title">$i18n{clearBrowsingData}</div>
       <div class="body">
         <div class="row">