Rename DriveProvider to ExternalProvider.

ui/file_manager/file_manager/foreground/js/file_transfer_controller.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.
 
 'use strict';
 
 /**
  * Global (placed in the window object) variable name to hold internal
  * file dragging information. Needed to show visual feedback while dragging
  * since DataTransfer object is in protected state. Reachable from other
@@ skipping 936 matching lines @@
 
     if (entries.length === 1) {
       // For single selection, the dragged element is created in advance,
       // otherwise an image may not be loaded at the time the 'dragstart' event
       // comes.
       this.preloadThumbnailImage_(entries[0]);
     }
 
     if (this.isOnDrive) {
       this.allDriveFilesAvailable = false;
-      this.metadataCache_.get(entries, 'drive', function(props) {
+      this.metadataCache_.get(entries, 'external', function(props) {
         // We consider directories not available offline for the purposes of
         // file transfer since we cannot afford to recursive traversal.
         this.allDriveFilesAvailable =
             !containsDirectory &&
             props.filter(function(p) {
               return !p.availableOffline;
             }).length === 0;
         // |Copy| is the only menu item affected by allDriveFilesAvailable.
         // It could be open right now, update its UI.
         this.copyCommand_.disabled = !this.canCopyOrDrag_();
@@ skipping 92 matching lines @@
           !event.ctrlKey) {
         return 'move';
       }
       if (event.shiftKey) {
         return 'move';
       }
     }
     return 'copy';
   },
 };