[MD settings] fix layout in startup urls and search engines iron-lists

chrome/browser/resources/settings/settings_shared_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 <link rel="import" href="settings_vars_css.html">
 
 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style include="cr-shared-style">
       /* Use <h2> as the "sub-header" mentioned in the UX design docs. */
       h2 {
         align-items: center;
@@ skipping 21 matching lines @@
         -webkit-margin-start: 16px;
         color: var(--paper-grey-600);
         flex-shrink: 0;
       }
 
       .separator + button[is='paper-icon-button-light'],
       .separator + paper-icon-button {
         -webkit-margin-start: var(--cr-icon-ripple-margin));
       }
 
-      .list-item paper-icon-button {
-        /* Workaround iron-list cutting off ripples on paper-icon-buttons.
-         * TODO(dschuyler): Can the end margin be done differently to allow for
-         * ripples to look like they are overlapping the margin. */
-        -webkit-margin-end: 0;
-      }
-
       /* See notes in .primary-button.
        * TODO(dschuyler): Remove unnecessary .secondary-button references. */
       paper-button {
         --paper-button: {
           -webkit-padding-end: var(--settings-button-edge-spacing);
           -webkit-padding-start: var(--settings-button-edge-spacing);
           color: var(--paper-grey-600);
           font-weight: 500;
           min-width: 1em;  /* A tighter fit than 5.14em for short buttons. */
           text-decoration: none;
@@ skipping 359 matching lines @@
         transform: rotate(-135deg);
       }
 
       .column-header {
         color: var(--paper-grey-600);
         font-weight: 500;
       }
     </style>
   </template>
 </dom-module>