Disallow dropping or pasting files to a volume with unrecognized partition.

ui/file_manager/file_manager/foreground/js/file_transfer_controller.js

Index: ui/file_manager/file_manager/foreground/js/file_transfer_controller.js
diff --git a/ui/file_manager/file_manager/foreground/js/file_transfer_controller.js b/ui/file_manager/file_manager/foreground/js/file_transfer_controller.js
index 337c5e431c0ee864176401126435b8d5d3728da3..6eba9d64e2d50d77293e065fa60e04dd54bf4456 100644
--- a/ui/file_manager/file_manager/foreground/js/file_transfer_controller.js
+++ b/ui/file_manager/file_manager/foreground/js/file_transfer_controller.js
@@ -1202,6 +1202,8 @@ FileTransferController.prototype.canPasteOrDrop_ =
     return false;
   var destinationLocationInfo =
       this.volumeManager_.getLocationInfo(destinationEntry);
+  if (destinationLocationInfo.volumeInfo.error)
+    return false;
   if (!destinationLocationInfo || destinationLocationInfo.isReadOnly)
     return false;
   if (!clipboardData.types || clipboardData.types.indexOf('fs/tag') === -1)
@@ -1328,6 +1330,8 @@ FileTransferController.prototype.selectDropEffect_ =
       this.volumeManager_.getLocationInfo(destinationEntry);
   if (!destinationLocationInfo)
     return new DropEffectAndLabel(DropEffectType.NONE, null);
+  if (destinationLocationInfo.volumeInfo.error)
+    return new DropEffectAndLabel(DropEffectType.NONE, null);
   if (destinationLocationInfo.isReadOnly) {
     if (destinationLocationInfo.isSpecialSearchRoot) {
       // The location is a fake entry that corresponds to special search.