[MD settings] side nav ink ripple on click

chrome/browser/resources/settings/settings_menu/settings_menu.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/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-submenu.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/paper-ripple/paper-ripple.html">
 <link rel="import" href="/icons.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-menu">
   <template>
     <style include="settings-shared">
       iron-icon {
         --iron-icon-fill-color: var(--settings-nav-grey);
         -webkit-margin-end: 24px;
       }
@@ skipping 30 matching lines @@
       .page-menu > div {
         margin-top: 8px;
       }
 
       .page-menu {
         --paper-menu-selected-item: {
           font-weight: 500;
         };
       }
 
+      paper-menu div {
+        position: relative;  /* Needed for paper-ripple. */
+      }
+
+      paper-ripple {
+        color: var(--google-blue-500);
+        opacity: .5;
+      }
+
       .page-menu paper-menu {
         --paper-menu-selected-item: {
           color: var(--google-blue-500);
           font-weight: 500;
         };
       }
 
       .page-menu div {
         -webkit-margin-start: 24px;
         align-items: center;
@@ skipping 108 matching lines @@
       <div class="separator"></div>
       <paper-submenu class="page-menu" data-page="about">
         <div class="menu-trigger" on-tap="openPage_" data-section="">
           $i18n{aboutPageTitle}
         </div>
       </paper-submenu>
     </paper-menu>
   </template>
   <script src="settings_menu.js"></script>
 </dom-module>