Show a local folder's size in QuickView.

ui/file_manager/file_manager/foreground/elements/files_metadata_box.html

 <!-- Copyright 2016 The Chromium Authors. All rights reserved.
   -- Use of this source code is governed by a BSD-style license that can be
   -- found in the LICENSE file.
 -->
 
 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 <link rel="import" href="files_metadata_entry.html">
 
 <dom-module id="files-metadata-box">
   <style>
@@ skipping 24 matching lines @@
 
     hr {
       border-color: white;
       margin-top: 31px;
       opacity: 0.24;
     }
   </style>
   <template>
     <div id="box">
       <div class="category" i18n-content="METADATA_BOX_GENERAL_INFO"></div>
-      <files-metadata-entry i18n-values="key:METADATA_BOX_FILE_SIZE" value="[[size]]"></files-metadata-entry>
+      <files-metadata-entry i18n-values="key:METADATA_BOX_FILE_SIZE" value="[[size]]" loading="[[isSizeLoading]]"></files-metadata-entry>
       <files-metadata-entry i18n-values="key:METADATA_BOX_MODIFICATION_TIME" value="[[modificationTime]]"></files-metadata-entry>
       <files-metadata-entry i18n-values="key:METADATA_BOX_MEDIA_MIME_TYPE" value="[[mediaMimeType]]"></files-metadata-entry>
 
       <div hidden="[[!hasFileSpecificInfo_(imageWidth, imageHeight, mediaTitle, mediaArtist)]]">
         <hr>
         <div class="category" hidden="[[!isImage_(type)]]" i18n-content="METADATA_BOX_IMAGE_INFO"></div>
         <div class="category" hidden="[[!isAudio_(type)]]" i18n-content="METADATA_BOX_AUDIO_INFO"></div>
         <div class="category" hidden="[[!isVideo_(type)]]" i18n-content="METADATA_BOX_VIDEO_INFO"></div>
         <files-metadata-entry i18n-values="key:METADATA_BOX_RESOLUTION" value="[[resolution_(imageWidth, imageHeight)]]"></files-metadata-entry>
         <files-metadata-entry i18n-values="key:METADATA_BOX_MEDIA_TITLE" value="[[mediaTitle]]"></files-metadata-entry>
         <files-metadata-entry i18n-values="key:METADATA_BOX_MEDIA_ARTIST" value="[[mediaArtist]]"></files-metadata-entry>
       </div>
     </div>
   </template>
 </dom-module>
 
 <script src="files_metadata_box.js"></script>