[MD History] Use proper shadows for cards.

chrome/browser/resources/md_history/synced_device_manager.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-list/iron-list.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-item/paper-item.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
 <link rel="import" href="chrome://resources/html/cr/ui/position_util.html">
 <link rel="import" href="chrome://history/shared_style.html">
 <link rel="import" href="chrome://history/synced_device_card.html">
 
 <dom-module id="history-synced-device-manager">
@@ skipping 41 matching lines @@
       }
 
       #sign-in-button {
         background-color: var(--google-blue-500);
         color: white;
         font-size: 14px;
         margin-top: 24px;
       }
 
       #synced-device-list {
+        @apply(--card-container-filter);
         padding-top: var(--first-card-padding-top);
       }
     </style>
     <div id="synced-device-list" hidden="[[!syncedDevices_.length]]">
       <template is="dom-repeat" items="[[syncedDevices_]]" as="syncedDevice">
         <history-synced-device-card device="[[syncedDevice.device]]"
             last-update-time="[[syncedDevice.lastUpdateTime]]"
             tabs="[[syncedDevice.tabs]]"
             separator-indexes="[[syncedDevice.separatorIndexes]]"
             search-term="[[searchTerm]]"
@@ skipping 11 matching lines @@
       <div id="illustration"></div>
       <div id="sign-in-promo">$i18n{signInPromo}</div>
       <div id="sign-in-promo-desc">$i18n{signInPromoDesc}</div>
       <paper-button id="sign-in-button" on-tap="onSignInTap_">
         $i18n{signInButton}
       </paper-button>
     </div>
   </template>
   <script src="chrome://history/synced_device_manager.js"></script>
 </dom-module>