I've try to use the file plugin on my android phone in 4.4 but I've got some strange problem with the callback function, succeed or fail.
When I try to access fileSystem (window.requestFileSystem)
The first time I don't receive the callback. But If I try a second time I've got 2 callBack.
I've try to debug the case. I 've figure that the 2 thread executing in java (JavaBind and file plugin) are synchronise on the NativeToJsMessageQueue. When the plugin enqueue Message and the java bind pop Message.
But I think the javabind finished before the file plugin, and never see the message in the queue. But the second time, I've got the 2 messages.
I think this is the same problem describe here :