DOMUI: A few fixes post-dialog refactoring.

chrome/browser/resources/options/browser_options_page.css

 
 #startupPageManagement.settings-list > :last-child {
   border-top: 1px solid #d9d9d9;
   padding: 5px 10px;
 }
 
 #startupPagesShortList {
   min-height: 0;
 }
 
@@ skipping 54 matching lines @@
 }
 
 #instantOption {
   margin-bottom: 0px;
 }
 
 #instantConfirmText {
   font-family: inherit;
   white-space: pre-wrap;
   width: 500px;
-  padding: 0px 16px 0px 16px;
 }
 
 #instantConfirmLearnMore {
   position: absolute;
   bottom: 18px;
-  -webkit-margin-start: 16px;
 }
 
 #startupAddButton {
   margin-left: 0;
   margin-top: 10px;
 }