MD Settings: convert paper-icon-button to paper-icon-button-light.

chrome/browser/resources/settings/device_page/storage.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/assert.html">
 <link rel="import" href="chrome://resources/html/cr/ui/focus_without_ink.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.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-icon-button/paper-icon-button-light.html">
 <link rel="import" href="drive_cache_dialog.html">
 <link rel="import" href="../prefs/prefs.html">
@@ skipping 198 matching lines @@
     <template is="dom-if" if="[[driveEnabled_]]">
       <div class="settings-box two-line" on-tap="onDriveCacheTap_"
           actionable$="[[hasDriveCache_]]" >
         <div class="start">
           $i18n{storageItemDriveCache}
           <div id="driveCacheSize" class="secondary">
             $i18n{storageSizeComputing}
           </div>
         </div>
         <button id="deleteButton" is="paper-icon-button-light"
-            aria-label="$i18n{storageItemDriveCache}"
+            class="icon-delete" aria-label="$i18n{storageItemDriveCache}"
             aria-describedby="driveSizeCache">
-          <iron-icon icon="cr:delete"></iron-icon>
         </button>
       </div>
     </template>
     <div class="settings-box two-line" on-tap="onBrowsingDataTap_" actionable>
       <div class="start">
         $i18n{storageItemBrowsingData}
         <div id="browsingDataSize" class="secondary">
           $i18n{storageSizeComputing}
         </div>
       </div>
@@ skipping 27 matching lines @@
             aria-describedby="otherUsersSize"></button>
       </div>
     </template>
 
     <settings-drive-cache-dialog id="storageDriveCache"
         on-close="onCloseDriveCacheDialog_">
     </settings-drive-cache-dialog>
   </template>
   <script src="storage.js"></script>
 </dom-module>