Remove support for calling UsbDeviceHandle methods from any thread

As of r613802 the last remaining user of this quirk in the
UsbDeviceHandle API has been migrated to the USB Mojo interface and so
the ability to call methods on UsbDeviceHandle from any thread and have
the callback posted back to the caller's thread can be removed.

Bug: 699790
Change-Id: Ieb3adecc2e971909aa69f612036d9bc0f5d69f31
Reviewed-on: https://chromium-review.googlesource.com/c/1364224
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Ovidio Henriquez <odejesush@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614538}
7 files changed