DOMUI Prefs: Remove border from list seletion, per mocks clarification

chrome/browser/resources/options/options_page.css

Index: chrome/browser/resources/options/options_page.css
diff --git a/chrome/browser/resources/options/options_page.css b/chrome/browser/resources/options/options_page.css
index 491b54393c11fd0b9a6a8029e20efc27db3cef95..4f24dc33523d41df6132143f5d2b76bcfbe94711 100644
--- a/chrome/browser/resources/options/options_page.css
+++ b/chrome/browser/resources/options/options_page.css
@@ -357,6 +357,7 @@ list > * {
   display: -webkit-box;
   height: 32px;
   border: none;
+  margin: 0;
 }
 
 list:not([disabled]) > :hover {
@@ -371,13 +372,6 @@ list > [selected]:hover {
   background-image: none;
 }
 
-list > [lead][selected],
-list:focus > [lead][selected] {
-  border-top: 1px solid #b2b2b2;
-  border-bottom: 1px solid #b2b2b2;
-  z-index: 3;
-}
-
 list[disabled] > [lead][selected],
 list[disabled]:focus > [lead][selected] {
   border: none;