Align GetFileInfo() between MtpManager and MtpDaemonClient.

MediaTransferProtocolDaemonClient currently provides a low-level
GetFileInfo() method, and MtpManager does the translation to the
high-level GetFileInfo() method that MTPDeviceTaskHelper understands.

Change MtpManager's GetFileInfo() from the high-level method to the
low-level method, so it acts more like a pass-through. Make
MTPDeviceTaskHelper handle the translation.

BUG=769630

Change-Id: I21e20b71d333a1ee7173071f04aaf2e37dd61844
Reviewed-on: https://chromium-review.googlesource.com/1080212
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565413}
9 files changed