[WebMIDI] Replace midi::MidiPortInfo with midi::mojom::PortInfo

This should make mojofying MidiHost and MidiMessageFilter easier.

Bug: 582328
Change-Id: I4dfcdb990cd938a63ec99f238020bc6ba325350f
Reviewed-on: https://chromium-review.googlesource.com/c/1244601
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Commit-Queue: Adithya Srinivasan <adithyas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600407}
22 files changed