Dropping files into the root list.

chrome/browser/resources/file_manager/js/file_manager.js

 // Copyright (c) 2012 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.
 
 /**
  * FileManager constructor.
  *
  * FileManager objects encapsulate the functionality of the file selector
  * dialogs, as well as the full screen file manager application (though the
  * latter is not yet implemented).
@@ skipping 530 matching lines @@
     var controller = this.fileTransferController_ = new FileTransferController(
         this.directoryModel_.getFileList(),
         this.directoryModel_.getFileListSelection(),
         GridItem.bind(null, this),
         this.copyManager_,
         this.directoryModel_);
     controller.attachDragSource(this.table_.list);
     controller.attachDropTarget(this.table_.list);
     controller.attachDragSource(this.grid_);
     controller.attachDropTarget(this.grid_);
+    controller.attachDropTarget(this.rootsList_, true);
     controller.attachCopyPasteHandlers(this.document_);
     controller.addEventListener('selection-copied',
         this.blinkSelection.bind(this));
     controller.addEventListener('selection-cut',
         this.blinkSelection.bind(this));
   };
 
   /**
    * One-time initialization of commands.
    */
@@ skipping 3771 matching lines @@
 
       handleSplitterDragEnd: function(e) {
         Splitter.prototype.handleSplitterDragEnd.apply(this, arguments);
         this.ownerDocument.documentElement.classList.remove('col-resize');
       }
     };
 
     customSplitter.decorate(splitterElement);
   };
 })();