Support for File Drop #1002

The drag/drop events don't natively expose the file path on file drop. For that, you have to invoke the getPathForFile function provided by the webUtils module. Unfortunately, this is not exposed by default (even less so when context isolation is turned on). Is there a way to invoke that function with the current possibilities, ideally without adding a preload script? And if it's not possible, is there a way to use a preload script without having it exposed as a physical file (e.g., loading from manifest stream)?