Refactoring file manager: moving volume mounting related code to a separate class.

chrome/browser/resources/file_manager/main.html

Index: chrome/browser/resources/file_manager/main.html
diff --git a/chrome/browser/resources/file_manager/main.html b/chrome/browser/resources/file_manager/main.html
index 469b726ceacc39d65bc662ad8aa5444249d1bc16..d067ae1ee527457f112b2cda2043994ee0939f48 100644
--- a/chrome/browser/resources/file_manager/main.html
+++ b/chrome/browser/resources/file_manager/main.html
@@ -68,6 +68,7 @@
       <script src="js/combobutton.js"></script>
 
       <script src="js/util.js"></script>
+      <script src="js/volume_manager.js"></script>
       <script src="js/directory_model.js"></script>
       <script src="js/file_copy_manager.js"></script>
       <script src="js/file_manager.js"></script>
@@ -184,7 +185,7 @@
               </button>
             </div>
           </div>
-          <div class='unmounted-panel'></div>
+          <div id='unmounted-panel'></div>
         </div>
       </div>
     </div>